Move every app to the isolated layout and release new versions of all 27 apps.

Frontend files move to source/apps/<id>/public/ and server code to source/apps/<id>/api.py and desktop.py beside it, matching the isolation mvmOS 0.28.0-beta enforces. Versions released: beambuilder 1.2.0, budget 1.4.0, calculator 1.3.0, calendar 1.2.0, chat 1.3.0, cost-splitter 1.4.0, cron-manager 1.6.0, findyourself 1.13.0, gamehub 1.12.0, git-manager 1.1.0, mvm2factor 1.1.0, mvmai 0.4.0, mvmsitebuilder 1.2.0, process-manager 1.3.0, qbit-dashboard 1.6.0, queuedesk 1.1.0, quotebuilder 2.4.0, rssfeed 1.3.0, server-manager 1.6.0, server-monitor 1.3.0, shoppinglist 1.1.0, statetracker 1.1.0, sudofall 1.12.0, system-info 1.2.0, tasks 1.4.0, telegramhub 1.1.0, yoursql 2.2.0.