The KDE Patchset Collection has been rebased on top of Qt 5.15.3

[Albert Astals Cid]

The KDE Patchset Collection has been rebased on top of Qt 5.15.3

Some patches have been droped, some are still needed since we carry patches newer than 1 year old.

Since this are rebases (to clearly show which patches are "ours", i.e. those on top of the v5.15.3-lts-lgpl tag) the kde/5.15 branches have been force-pushed to, don't get scared when fetching tells you that a force-update happened.

Cheers,
  Albert