Add custom hex2bin implementation for 5.3

Fixes https://github.com/owncloud/core/issues/11004
Add X-UA-Compatible to all templates

Replaces https://github.com/owncloud/core/pull/10850
Merge pull request #11007 from owncloud/replaces-10850

Add X-UA-Compatible to all templates
fix notification visibility, fix #11016
Merge pull request #11006 from owncloud/addCustomHex2BinImplementationBecauseSupporting53IsSomethingReallyReallyCoolAndWeAreObviouslySomeOfTheCoolGuys

Add custom hex2bin implementation for 5.3
improve style of checkmark icon, less bold, fitting ownCloud style
fix size of toggle icon, make container square
fix svg of calendar filetype icon
fix folder icon alignment, fix #10866
Merge pull request #11018 from owncloud/fix-notification-layer

fix notification visibility, fix #11016
Merge pull request #11022 from owncloud/icons-fix

Fix icons