Extensions missing the "Some features may require payment" flag

[anewuser]

Please add the Some features may require payment flag to these extensions:

• Easy Youtube Video Downloader Express - requires a paid upgrade to download videos in 1080p
• ModHeader - free users can only create up to 10 rules

┆Issue is synchronized with this Jira Task

[KevinMind]

Old Jira Ticket: https://mozilla-hub.atlassian.net/browse/ADDFRNT-218