Backport Firebird 3.0 support

it is mostly the same as 2.5 but there is no docker container for 2.5
so this is neccesary to have code tested on github

Author: alex-kulakov

Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/DriverFactory.cs

@@ -62,6 +62,8 @@ private static SqlDriver CreateDriverInstance(
       if (coreServerInfo.ServerVersion.Major == 2 && coreServerInfo.ServerVersion.Minor == 5) {
         return new v2_5.Driver(coreServerInfo);
       }
+      if (coreServerInfo.ServerVersion.Major == 3)
+        return new v3_0.Driver(coreServerInfo);
 
       return null;
     }

Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v3_0/Compiler.cs

@@ -0,0 +1,18 @@
+// Copyright (C) 2025 Xtensive LLC.
+// This code is distributed under MIT license terms.
+// See the License.txt file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Xtensive.Sql.Drivers.Firebird.v3_0
+{
+  internal class Compiler : v2_5.Compiler
+  {
+    protected internal Compiler(SqlDriver driver)
+      : base(driver)
+    {
+    }
+  }
+}

Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v3_0/Driver.cs

@@ -0,0 +1,30 @@
+// Copyright (C) 2025 Xtensive LLC.
+// This code is distributed under MIT license terms.
+// See the License.txt file in the project root for more information.
+
+using System;
+using Xtensive.Sql.Info;
+using Xtensive.Sql.Compiler;
+
+namespace Xtensive.Sql.Drivers.Firebird.v3_0
+{
+  internal class Driver : v2_5.Driver
+  {
+    protected override Sql.TypeMapper CreateTypeMapper() => new TypeMapper(this);
+
+    protected override SqlCompiler CreateCompiler() => new Compiler(this);
+
+    protected override SqlTranslator CreateTranslator() => new Translator(this);
+
+    protected override Model.Extractor CreateExtractor() => new Extractor(this);
+
+    protected override Info.ServerInfoProvider CreateServerInfoProvider() => new ServerInfoProvider(this);
+
+    // Constructors
+
+    public Driver(CoreServerInfo coreServerInfo)
+      : base(coreServerInfo)
+    {
+    }
+  }
+}

Orm/Xtensive.Orm.Firebird/Sql.Drivers.Firebird/v3_0/Extractor.Queries.cs

@@ -0,0 +1,75 @@
+// Copyright (C) 2021 Xtensive LLC.
+// This code is distributed under MIT license terms.
+// See the License.txt file in the project root for more information.
+
+namespace Xtensive.Sql.Drivers.Firebird.v3_0
+{
+  internal partial class Extractor
+  {
+    protected override string GetExtractTableColumnsQuery()
+    {
+      return @"
+select   schema
+        ,table_name
+        ,ordinal_position
+        ,column_name
+        ,field_type
+        ,column_subtype
+        ,column_size
+        ,numeric_precision
+        ,-numeric_scale as numeric_scale
+        ,character_max_length
+        ,(1 - coalesce(column_nullable,0)) as column_nullable
+        ,column_default
+        ,relation_type
+from     (select   cast(null as varchar(30)) as schema
+                  ,trim(rfr.rdb$relation_name) as table_name
+                  ,trim(rfr.rdb$field_name) as column_name
+                  ,fld.rdb$field_sub_type as column_subtype
+                  ,cast(fld.rdb$field_length as integer) as column_size
+                  ,cast(fld.rdb$field_precision as integer) as numeric_precision
+                  ,cast(fld.rdb$field_scale as integer) as numeric_scale
+                  ,cast(fld.rdb$character_length as integer) as character_max_length
+                  ,cast(fld.rdb$field_length as integer) as character_octet_length
+                  ,rfr.rdb$field_position as ordinal_position
+                  ,trim(rfr.rdb$field_source) as domain_name
+                  ,trim(rfr.rdb$default_source) as column_default
+                  ,trim(fld.rdb$computed_source) as computed_source
+                  ,fld.rdb$dimensions as column_array
+                  ,coalesce(fld.rdb$null_flag, rfr.rdb$null_flag) as column_nullable
+                  ,0 as is_readonly
+                  ,fld.rdb$field_type as field_type
+                  ,trim(cs.rdb$character_set_name) as character_set_name
+                  ,trim(coll.rdb$collation_name) as collation_name
+                  ,trim(rfr.rdb$description) as description
+                  ,cast(rr.rdb$relation_type as integer) as relation_type
+          from     rdb$relations rr join rdb$relation_fields rfr on rfr.rdb$relation_name = rr.rdb$relation_name
+                   left join rdb$fields fld on rfr.rdb$field_source = fld.rdb$field_name
+                   left join rdb$character_sets cs
+                      on cs.rdb$character_set_id = fld.rdb$character_set_id
+                   left join rdb$collations coll
+                      on (coll.rdb$collation_id = fld.rdb$collation_id
+                      and coll.rdb$character_set_id = fld.rdb$character_set_id)
+          where    rr.rdb$relation_type in (0, 4, 5) and rr.rdb$relation_name not starts with 'RDB$' and rr.rdb$relation_name not starts with 'MON$'
+          order by table_name, ordinal_position)";
+    }
+
+    protected override string GetExtractUniqueAndPrimaryKeyConstraintsQuery()
+    {
+      return @"
+select     cast(null as varchar(30)) as schema
+          ,trim(rel.rdb$relation_name) as table_name
+          ,trim(rel.rdb$constraint_name) as constraint_name
+          ,trim(rel.rdb$constraint_type) constraint_type
+          ,trim(seg.rdb$field_name) as column_name
+          ,seg.rdb$field_position as column_position
+from       rdb$relation_constraints rel
+left join rdb$indices idx on rel.rdb$index_name = idx.rdb$index_name
+left join rdb$index_segments seg on idx.rdb$index_name = seg.rdb$index_name
+where      rel.rdb$constraint_type in ('PRIMARY KEY', 'UNIQUE')
+           and rel.rdb$relation_name not starts with 'RDB$'
+           and rel.rdb$relation_name not starts with 'MON$'
+order by   rel.rdb$relation_name, rel.rdb$constraint_name, seg.rdb$field_position";
+    }
+  }
+}