Add support for "Move to file" interactive code action

[guillaumebrunerie]

This adds support for the "Move to file" code action for the JavaScript/TypeScript language server, fixing #4649.
Note that this pull request depends on typescript-language-server/typescript-language-server#987 being merged first.

This pull request does the following:

• sets the new supportsMoveToFileCodeAction initialization option of typescript-language-server to t,
• uses action-filter to intercept the "Move to file" code action, ask the user for a file, and add the appropriate arguments to the command.

Note that "Move to file" doesn’t seem to work if the destination file exists but isn’t open in Emacs, not sure if that’s how it behaves in VSCode as well or if there is a way to work around that?

[guillaumebrunerie]

typescript-language-server/typescript-language-server#987 has been merged now, so this pull request is ready to be merged to add support for "Move to file" in Emacs.

[dzhu]

Hello! I'm not affiliated with the project, but I was excited to see this PR open, and I tried it out myself. I had to make a change to get it to work, though: there is the lsp-use-plists option, which changes the internal objects from hashes to plists, so you should use the lsp-get and lsp-put wrapper functions as shown in the inline suggestion. That will let the code work whichever way the option is set.

Thanks for putting the pieces together to make this feature work!

[guillaumebrunerie]

@dzhu Thank you for the suggestion! I didn’t know about lsp-get and lsp-put and it did feel wrong to use gethash and puthash directly, it’s much better now.