fix(lsp): prevent duplicate trailing punctuation in clangd

[soifou]

Strip the trailing angle bracket or quote from clangd file completion items to avoid duplicated characters.

This issue is a side effect of the recent change in compensate_for_cursor_movement (hope this is the only one). Clangd deliberately includes the closing punctuation in all "file" completion candidates. This behavior is opinionated and there is currently no way to opt out (see clangd/clangd#2277).

While it bothers me to add this downstream workaround, I believe it is reasonable to let users handle the closing character themselves—either manually or via a pairs plugin as they do when using the "path" source or from other lsp.

Feel free to close this PR if you think there is a better solution.

Closes #1989

[lixiao189]

Look at this reply: clangd/clangd#1041 (comment)
I think that the better way is to replace the inserted text with LSP suggestion item instead of stripping the text in the end?

[saghen]

As mentioned by the clangd folks, the replace range sent at the time of the request is correct, so we should try to fix the root cause in the compensate_for_cursor_movement. Quite a tricky one to get right...

Fyi, I believe the issue with disable-next-line is actually a lua-ls issue: #1985 (comment)