feat: Specify project path in LSP workspace settings

Description

When this workspace setting is specified the path is used to build up additional context for generating code suggestions.

Related Issues

1. Resolves #1153 (closed).
2. Relates to gitlab-org/editor-extensions/gitlab-lsp!171 (merged).

How has this been tested?

• Unit test coverage
• Smoke test in VS Code with local extension version
• Smoke test in Web IDE with local extension version (⚠ not done yet)

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation
• Chore (Related to CI or Packaging to platforms)
• Test gap