Organize imports for TypeScript and JavaScript

[saixiaoxi]

In this PR:

• Port organize imports functionality for TypeScript and JavaScript
• Preserve blank line groupings to respect user's logical organization
• Support all import types: side-effect, type-only, namespace, default, named, and require

Imports are sorted by:

1. Module type: absolute imports before relative imports
2. Import kind: side-effect → type-only → namespace → default → named → require
3. Alphabetically within each category

The feature is exposed via LSP workspace/executeCommand with command typescript-go.organizeImports and integrated into the VS Code extension as the "Sort Imports" command.

Fixes #1724