Get rid of svg scaling hack for Firefox in the apps management

[MorrisJobke]

• introduced with Fix icons on App page in FF #905
• see

  server/settings/js/apps.js

  Lines 237 to 241 in 1444c1d

  	// weird hack because in Firefox everything is 4 times as big (doubled in width and doubled in height)
  	// TODO: replace this with a proper solution
  	if($.browser.mozilla) {
  	img = '<svg width="72" height="72" viewBox="0 0 36 36">';
  	}

cc @rullzer @juliushaertl @Bugsbane @raghunayyar @Mar1u5

[juliusknorr]

Hmm, bad that we had such a bug 😢

I guess we should get rid of the svg filter inversion completely to avoid such side-effects. At first it looked like an easy way to use this, but it wasn't.

My idea would be to add some IconController to core that will just read the svg from the app replace color codes and return a new svg image.(just similar to what is done https://github.com/nextcloud/server/pull/840/files#diff-55c944adbad26e06ef3fc9b2b219f281R275)
Then we could just go with the default -tag that works everywhere.
What do you think about that?

[rullzer]

While that would be the 'easy' solution. Something that we can do client side scales a lot better.

[rullzer]

Ok it was the viewBox thing that was missing. This basically made FF (and others) say I don't know how to scale it.

It is fixed now.

[MorrisJobke]

It is fixed now.

In #905