QML version of the Desktop Grid effect

Replace completely the old desktop grid effect with a QML version. Aims to feature parity and be a change as transparent as possible for the user.

BUG: 433071 BUG: 452625 BUG: 443971 BUG: 437121 BUG: 452925 BUG: 437928 BUG: 452439 BUG: 288530 BUG: 450254 BUG: 450106 BUG: 447832 BUG: 449960 BUG: 416576 BUG: 441862 BUG: 444859 BUG: 445999 BUG: 422117 BUG: 404627 BUG: 435483 BUG: 420744 BUG: 435482 BUG: 427055 BUG: 333445 BUG: 429120 BUG: 427391 BUG: 409295 BUG: 294322 BUG: 356955 FIXED-IN: 5.25