plugin: support deprecated code completion items

[esterw1109]

Issue-8310: Deprecated code completions crash

Signed-off-by: Esther Perelman wwr1109@gmail.com

What it does

Fixes #8310
Fixes #8475

How to test

Steps to reproduce on #8310

Review checklist

• as an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• as a reviewer, I agree to behave in accordance with the review guidelines

[shahar-h]

I can confirm that #8475 is resolved with this fix.

[vince-fugnitto]

The changes look good to me 👍

I confirmed that the vscode-builtin-css-language-features extension works correctly
(provides auto-completion).

[amiramw]

#8310 with this change display code completion which didn't happen before.

However it doesn't show any indication for the deprecated one:

While in vscode it showed:

@shahar-h @vince-fugnitto, did you get the same behavior in your tests?

If so do you think this gap should be part of this PR or a separate issue?

[shahar-h]

It's strange, I couldn't find any deprecated completion items in css.
However, I noticed that in your sample repo you use deprecated property in completion item, which is deprecated in favor of tags, see: https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_completion.

Try to use tags instead, and in addition maybe also deprecated property should be supported in CompletionItem.

[amiramw]

Also for tags: [1] (1 is deprecated) I don't get any indication in the UI.

[amiramw]

Approved,
@esterw1109 please open another issue for the UI indication

[danidoedel]

When will this PR be merged? This bug bothers me quite some time already and I can't wait to see it fixed 😁

[EstherPerelman]

Approved,
@esterw1109 please open another issue for the UI indication

Opened #8552