Added keywords for 1C query syntax

[AlexandraG-code]

Description

Added missing keywords for 1C query language including OPERATOR, WHERE, ORDER BY, GROUP BY, and other SQL-like constructs specific to 1C platform.

Motivation and Context

Currently, some 1C query language keywords are not properly highlighted. This change improves the developer experience when working with 1C queries by providing more accurate syntax highlighting.

How Has This Been Tested?

• Tested with various 1C query examples
• Verified that existing highlighting for other languages remains unchanged
• Checked different color themes

Types of changes

• New feature (non-breaking change which adds functionality)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.