[cursors] Add 36px (1.5 scaling) size for Breeze and Breeze Snow Cursors

On a desktop with 1.5 scaling the cursor sizes 24 (factor 1) and 48 (factor 2)
are both not very well suited. Therefore add a 1.5 scaled cursor, since it's a
common scaling factor.

For that I edited the build script and rebuilt everything with it, which also
replaced some unnecessary file duplicates with symlinks.

BUG: 348603

Reviewers: #plasma

Subscribers: plasma-devel, broulik

Tags:  #plasma

Differential Revision: https://phabricator.kde.org/D4358