Theia: Implement SelectionRange and SelectionRangeProvider

[tolusha]

Description

css-language-features, html-language-features, json-language-features builtin extensions failed due to unimplemented VS Code API.

https://github.com/Microsoft/vscode/blob/8795a9889db74563ddd43eb0a897a2384129a619/src/vs/vscode.d.ts#L3842
https://github.com/Microsoft/vscode/blob/8795a9889db74563ddd43eb0a897a2384129a619/src/vs/vscode.d.ts#L3863

[akosyakov]

Right now html and css coming from monaco. It's baked in the generator: https://github.com/eclipse-theia/theia/blob/b8c5e18530b93c5a8b7a1890b68f5bcc202e5817/dev-packages/application-manager/src/generator/webpack-generator.ts#L56-L57

We should make it optional somehow. Otherwise there would be duplicate proposals from monaco and vs code built-in extensions.

[vzhukovs]

Implemented via https://github.com/eclipse-theia/theia/pull/7534