Fix install of bought games and launch of games with spaces in paths

Three bugs, all seen on Bubble Tower (itch.io game 4845491):

- Installs of bought games failed with "you must buy this game to download".
  butlerd only learns itch.io download keys from Fetch.ProfileOwnedKeys,
  which the library skips when "show_purchases" is off (the listing then
  comes from collections, so owned games still show up). butlerd queued
  the install without credentials and itch.io rejected the build request.
  Install.Queue is now retried once after a fresh owned-keys sync when
  itch.io answers with that error.

- The install-options upload dropdown never applied the user's pick: it
  offers "<name>  (<size>)" while _pick_upload compared against the bare
  displayName/filename, so every multi-upload game silently fell back to
  the default upload. The label format is now shared through
  UPLOAD_SIZE_SEPARATOR and the name prefix counts as a match.

- Games whose receipt carries no launch block were resolved by scanning
  for the largest executable and splitting "size path" on a space, which
  truncated the path of any file with a space in its name (Unity's
  "unity default resources") and pointed the launch at a file that does
  not exist. Sizes and paths are now tab-separated, and Unity's data
  files are skipped.

plugin.json

@@ -1,7 +1,7 @@
 {
   "plugin.id": "itch",
   "plugin.name": "itch.io",
-  "plugin.version": "0.1.39",
+  "plugin.version": "0.1.41",
   "plugin.min-api-version": "1.1.0",
   "plugin.link": "https://forge.thergic.ar/jose/itchio-opengamepadui-plugin",
   "plugin.source": "https://forge.thergic.ar/jose/itchio-opengamepadui-plugin",