Allow apps to opt-out of any shipped javascript libraries

[juliusknorr]

From #7738

My idea here was to maybe provide a set of building blocks, that are not shipped within Nextcloud itself, but within the app via NPM/yarn/whatever modules, that the app itself need to ship.
Should we make this a breaking change or require apps to opt-in by using a special info.xml flag like ?
EDIT: we could also make the transition slowly by:

opt-in using in Nextcloud 14
opt-out using in Nextcloud 15
have a breaking change with Nextcloud 16

Those are the components we should try to migrate away from jQuery, so we don't have a dependency on that for normal app pages (feel free to add stuff I might have forgotten):

• App menu
• Notifications (should already be fine since it is a webpack bundled app)
• Contacts menu
• Popover handling
• Search
• avatar plugin
• placeholder plugin
• heartbeat
• cron
• tooltips
• l10n (uses $.get)

@nextcloud/javascript

[georgehrke]

Alternatively we could also use https://api.jquery.com/jquery.noconflict/
So instead of abolishing jQuery completely from the server, we just don't advertise it as window.$ or window.jQuery, but window.serverJQuery or similar.

[juliusknorr]

@georgehrke Oh that looks interesting, so we just need to adjust the code to use the serverJQuery version.

[skjnldsv]

Should we add there the to-be-created components as well?

[rullzer]

Some of those should maybe have their legacy (jquery) variant lying around for a few releases. Like the avatar and placeholder. Make sure their original is still their so it works for everybody.

Add some warnings or whatever to tell devs to move to the new stuff.

[juliusknorr]

Closing as we are slowly deprecating the shipped global libraries now and https://github.com/orgs/nextcloud/projects/31 provides a much better overview of what is still legacy js.