Fix mentions rendering in comment editor

[artonge]

NcRichContentEditable needs an index of users to properly display them[0].
This commit adds a caching logic and provides it to NcRichContentEditable.

[0] https://github.com/nextcloud/nextcloud-vue/blob/01dc781d18e2d2a81fed6ad578b90532709b7e1d/src/mixins/richEditor/index.js#L106-L119

Fix #35047

[danxuliu]

This is already addressed in #35053, but it was not reviewed yet :-)

[artonge]

Closing in favor of #35053

[artonge]

Reopening after discussion with @danxuliu :)

[miaulalala]

LGTM

[miaulalala]

/backport to stable25

[miaulalala]

/backport to stable24

[danxuliu]

Tested and works 👍

One thing, though. It seems that editing a comment that ends with a mention in Firefox does not work (or, at least, it does not work here :-) ):

• Use Firefox
• Send a new comment which is just a mention (like @user0)
• Edit that comment
• The cursor does not appear, and typing is not reflected in the comment. On the other hand, if the message was hello @user0 it is possible to place the cursor at the beginning with the mouse and type there, but not at the end.

But I guess this is not a problem caused by this pull request (well, it is because now there are rendered mentions, but you know what I mean ;-) ).

[danxuliu]

/backport to stable23

[artonge]

/backport to stable25

[artonge]

/backport to stable24

[backportbot-nextcloud]

The backport to stable25 failed. Please do this backport manually.

[backportbot-nextcloud]

The backport to stable25 failed. Please do this backport manually.

[backportbot-nextcloud]

The backport to stable24 failed. Please do this backport manually.

[backportbot-nextcloud]

The backport to stable24 failed. Please do this backport manually.

[backportbot-nextcloud]

The backport to stable23 failed. Please do this backport manually.