Tag loading

[kesselb]

If you are a heavy tags user you may run into performance issues.
Especially the user interface is somewhat unusable with a large number of tags.

The tag multi select loads all tags via dav. Filtering is done by select2.
I expect the vue migration to fix some of those issues.

This PR addresses some low hanging fruits:

e1d9b0b: Add minimumInputLength for select2. This will delay the loading of the tags by a few keystrokes. It does not improve the performance but it feels a bit less sluggish. But a minimum input length is also a breaking change and everyone using short tags is probably very unhappy about this 😕 ❓

1bfac6d: When you start typing tags are fetched via xhr. fetched is there to keep track if the data was loaded already. However we have 3 states: not loaded, loading and loaded. If the user continues to type and fetched is false another xhr request is started. This commit is here to address the loading state and prevent another xhr request.

Before	After
Screencast from 15.09.2022 12:26:43.webm	Screencast from 15.09.2022 16:26:20.webm

79b4c4f: It's an optional change. Adding 10k dom elements put some pressure on my browser. I'm not familiar with select2 and the internals however in my tests I noticed that we emit a deprecation warning for each tag. I rewrote getDescriptiveTag and it seems to help a little bit.

Add 10k tags via occ:

#!/bin/bash

for i in {1..10000}
do
	php occ tag:add "Tag$i" "public"
done

[PVince81]

👍