epm install: add --download_only (save after repack) and --direct + --download_only (save before repack)

- epm pack 1c83-client: fixes
- epm repack rstudio: fix chrome-sandbox
- epm play steam: add install Steam from the repo

- epm play: rewrite, add applications list support, use app=version form
- add epm pack
- epm play: add initial portproton support
- epm pack: add 1c83-client support
- rewrite all browser-codecs install via epm pack
- epm play opera: rewrite, fix other systems install
- epm play: move wine to play list
- epm repack: add r7-office (with support for 7.3)