Split "page" context menu from links
As far as Firefox is concerned, a context menu entry on the page itself has no "target" and so any `targetUrlPatterns` will cause the menu entry not to show. This patch splits the "page" context from anything with a link or source, so that we can set `targetUrlPatterns` for those, and `documentUrlPatterns` for the "page" menu. This has the added benefit of not allowing to share internal browser pages, such as "New Tab", while still allowing to send http(s) links on those pages. While at it, also support the "tab" context in Firefox which adds an entry to the tab button on the tab bar.
Showing with 94 additions and 47 deletions