Custom Campaign select screen:
- Show all installed custom campaigns, not just the ones that support the current mode.
- Disable list items for campaigns that don't support the current mode, and sort them to the bottom of the list.
- Fixed some uninitialized text fields when no campaign is selected.
- Moved an informational string so it doesn't overlap the campaign list.

Workshop Publishing Tool:
- Removed the file count from the download progress bar to avoid confusion when stale meta-data indicates there are more files than actually exist.
- Don't show the download progress bar if no valid files were found.
- Fixed the "Failed to write file chunk…" error message not correctly showing the number of bytes written.