feat(DATAGO-122877): Implement MSSQL tool with pyodbc driver

[Hugo-Pare]

What is the purpose of this change?

Adds Microsoft SQL Server (MSSQL) support to the sam-sql-database-tool plugin, expanding database compatibility beyond PostgreSQL, MySQL, and MariaDB.

How was this change implemented?

• pyproject.toml: Added pyodbc dependency for MSSQL connectivity and testcontainers[mssql] for testing
• database_service.py: Added MSSQL-specific row count query using sys.tables/sys.partitions and extended string type detection to include NVARCHAR, NCHAR, NTEXT
• conftest.py: Added MSSQL test container configuration with SqlServerContainer and pyodbc connection URL
• test_data.py: Set autoincrement=False on all primary keys to allow explicit ID inserts (MSSQL IDENTITY column restriction)
• test_sql_tool.py: Cast rating to Float in aggregation test to handle MSSQL integer division behavior
• test_config_features.py: Added dialect-specific ALTER TABLE syntax (MSSQL omits COLUMN keyword in ADD)
• README.md: Updated documentation with MSSQL connection string example

Key Design Decisions

• Chose pyodbc over pymssql as it's more widely supported and Microsoft-recommended, though it requires an ODBC Driver to be installed on the host system
• Used autoincrement=False in test tables rather than modifying INSERT statements to keep test queries database-agnostic

How was this change tested?

• Manual testing: Connected to local MSSQL Docker container and verified queries execute correctly
• Unit tests: Existing unit tests pass
• Integration tests: All integration tests pass across PostgreSQL, MySQL, MariaDB, and MSSQL (223 tests total)
• Known limitations: Requires an ODBC Driver for SQL Server installed on the host system

Is there anything the reviewers should focus on/be aware of?

• The MSSQL connection string requires TrustServerCertificate=yes for self-signed certificates (common in dev/test environments)
• Users will need to install the ODBC Driver separately - this is a system-level dependency that cannot be bundled with the Python package

[github-actions]

✅ SonarQube Quality Gate - All Passed

Plugin	Quality Gate Status	Analysis
sam-sql-database-tool	✅ Passed	See analysis details on SonarQube

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Quality gate checks are run for each modified plugin. Click the SonarQube links above for detailed analysis.

[m9p909]

• add mssql row count
• add integration tests
• add documentation for MSSQL
• Add mssql specific text types