Added tests for parquedit.py

[roarv2]

Changes summary

• Updated multiline SQL string formatting in src/ssb_parquedit/parquedit.py for attach, create table from parquet, and fill table operations.
• Minor whitespace cleanup in docs/conf.py and noxfile.py.
• Added comprehensive unit tests in tests/test_parquedit.py covering initialization, context management, validation, schema translation, table creation from DataFrame/Parquet, partitioning, description, and fill behaviors.
• Purpose: Improve code style/readability and significantly increase test coverage and behavior verification.
• Overall code quality: Testing depth improved with clear isolation via dependency stubbing. The parquedit.py edits are style-only but risk changing whitespace in SQL strings; behavior likely unchanged. No security-sensitive changes introduced.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud