v1.2.2 NDJSON Generation, Parler support

This beta release of Zeeschuimer incorporates the following updates and fixes:

• Refactoring of the NDJSON generation code so the extension no longer crashes when trying to download or upload datasets of more than ~12,500 items
• Support for collecting Parler posts (from the feed and search results)
• An upload progress indicator that actually works and allows for cancelling the upload
• The NDJSON button now indicates that it is busy while the NDJSON is being generated
• The extension can now use Firefox's automatic updating system to update to new versions
• Assorted small tweaks and fixes