Support string column auto-reserve to insertsion

[zhanglei1949]

def test_insert_string_column_exaustion():
    db_dir = "/tmp/test_insert_string_column_exhaustion"
    shutil.rmtree(db_dir, ignore_errors=True)
    db = Database(db_path=db_dir, mode="w")
    conn = db.connect()
    conn.execute("CREATE NODE TABLE Person(id INT64, name STRING, PRIMARY KEY(id));")
    # by default the string column has maximum length 256
    conn.execute("CREATE (p: Person {id: 1, name: 'a'});")
    conn.execute("CREATE (p: Person {id: 2, name: 'b'});")
    conn.execute("CHECKPOINT;")
    conn.close()
    db.close()

    db2 = Database(db_path=db_dir, mode="w")
    conn2 = db2.connect()
    str_prop = "a" * 255
    for i in range(10000):
        conn2.execute(f"CREATE (p: Person {{id: {i+3}, name: '{str_prop}'}});")
    res = conn2.execute("MATCH (p: Person) RETURN count(p);")
    records = list(res)
    assert records == [[10002]], f"Expected value [[10002]], got {records}"
    conn2.close()
    db2.close()

    db3 = Database(db_path=db_dir, mode="w")
    conn3 = db3.connect()
    conn3.execute("CREATE REL TABLE Knows(FROM Person TO Person, note STRING);")
    conn3.execute(
        "MATCH (a: Person), (b: Person) WHERE a.id = 1 AND b.id = 2 CREATE (a)-[:Knows {note: '12'}]->(b);"
    )
    conn3.execute(
        "MATCH (a: Person), (b: Person) WHERE a.id = 3 AND b.id = 4 CREATE (a)-[:Knows {note: '34'}]->(b);"
    )
    conn3.execute("CHECKPOINT;")
    db3.close()

    db4 = Database(db_path=db_dir, mode="w")
    conn4 = db4.connect()
    res = conn4.execute("MATCH (a: Person)-[k: Knows]->(b: Person) RETURN k.note;")
    records = list(res)
    assert records == [
        ["12"],
        ["34"],
    ], f"Expected value [['12'], ['34']], got {records}"
    str_prop = "a" * 255
    for i in range(100):
        conn4.execute(
            f"MATCH (a: Person {{id: 1}}), (b: Person {{id: 2}}) CREATE (a)-[:Knows {{note: '{str_prop}'}}]->(b);"
        )

    conn4.close()