feat: add directory SQL formatting command

[MayerTim]

Summary

Adds a new SQLovely command for formatting multiple SQL files inside a selected directory.

Changes

• Adds SQLovely: Format SQL Files in Directory
• Opens a directory picker after running the command
• Recursively formats *.sql files in the selected directory
• Skips common local/build folders such as .git, node_modules, out and dist
• Shows a confirmation dialog before changing files
• Skips dirty/open files to avoid overwriting unsaved editor changes
• Shows a summary with formatted, unchanged, skipped and failed file counts
• Runs formatting without SQLovely Extras by default

Validation

• npm run check
• npm test
• npm run package:vsix