[FEATURE] Dependency View in Explorer

[SpontanCombust]

VSCode allows for adding custom tabs to Explorer's window. Use this to add a view, which will list all active contents. Do this in similar manner to rust-analyzer's "Rust dependencies" tab.

• [x] Add "WitcherScript Contents" Explorer view which will show file trees of contents from outside the workspace
• [x] For each content display its metadata and files
• [x] Add "contentKind" to ContentInfo (raw/wide-project/redkit-project)
• [x] clicking on a file should open it
• [x] opening a file from workspace should be writable and outside of workspace read-only
• [x] if there are no projects in the workspace (and thus no contents were established) the view should display a welcome message with init/create project buttons

[SpontanCombust]

View with available script content:

View without available script content: