Add support for references code lenses in VS Code extension

[mjbvz]

When switching to tsgo, the references code lenses are a noticeable missing feature

I believe this feature can be implemented entirely on the extension side. Today we use navtree and references requests to implement them. We could do the same with tsgo or they could be implemented natively using the LSP

[jakebailey]

I suspect this would be better implemented on the server side (way less data transfer), since code lenses are in the LSP (https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_codeLens), but actually associating something with the code lens means using client command to then link to references/implementations.

For references, the VS Code command is editor.action.showReferences: https://github.com/microsoft/vscode/blob/5c88b1d51aa1c6758b50543f990e2898eefdaaf8/extensions/typescript-language-features/src/languageFeatures/codeLens/referencesCodeLens.ts#L56C33-L56C61

Implementations says the same command (https://github.com/microsoft/vscode/blob/5c88b1d51aa1c6758b50543f990e2898eefdaaf8/extensions/typescript-language-features/src/languageFeatures/codeLens/implementationsCodeLens.ts#L74) which is confusing.

I don't think we need custom client registered commands for error cases, but we will need to check that the client is one that has these commands. Not sure about VS.