Increase performance with `prop_add_list()` and `sign_placelist()`

[noscript]

Please consider using prop_add_list() and sign_placelist() when placing multiple signs and properties. From my experience the performance impact is huge when adding 100+ elements at once.

There is currently a noticeable lag with semantic highlight and diagnostic text properties. I suspect it could be improved significantly by using the list functions.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[prabirshrestha]

New semantic highlighting does use prop_add_list(). Please give it a try at https://github.com/prabirshrestha/vim-lsp/pull/1275.

Diagnostics needs to be updated.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[noscript]

Thank you for the effort!