Search sharees on lookup server when explicitly requested by user

[ChristophWurst]

Before

Sharee search either never or always goes to lookup server, depending on admin setting.

Now

Sharee search by default just searches locally. If no results are returned and the lookup server is not explicitly disabled by the admin, the user gets the option to search globally. This retriggers the search request but also includes lookup server results.

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Note: I had some difficulties connection to the lookup server form my dev server but the default empty response for that is sufficient for testing :)

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Todo

• Design does not look like @jancborchardt's mockup (search icon has to be moved before the text)

[jancborchardt]

For the record here’s the mockup :)

Btw @ChristophWurst, seems some unrelated files were edited maybe in the fixup?

Conflicting files

apps/accessibility/js/accessibility.js
apps/accessibility/js/accessibility.js.map

[ChristophWurst]

There seem to be a few UI hiccups here and there (already seen when working on #14180, hence this might be an old bug) but this generally works and also looks like @jancborchardt's mockup.

[schiessle]

Tested and works great! 👍

[ChristophWurst]

Thanks for testing! 🙌

I squashed my fixup commits and rebased onto master.

[MorrisJobke]

Tested and works 👍

[ChristophWurst]

Aaaaaaah now CI looks good :) Let me do a final squash&rebase