Pivot spookfox-org-tabs to be a tab archive

[bitspook]

Instead of treating it as a replacement for browser's tab-bar, org-tabs should
have following features:

• Archive presently open tabs

  When I have a ton of open tabs, I want to organize them and keep only the relevant ones open. To support this, Spookfox should allow me to capture all open tabs, and close (in browser) the ones I choose to archive.

• Open a tab or tab group

  Allow opening an archived tab, or all the tabs from a tab-group. When a tab is opened, it should be removed from the archive (i.e the org file). A tab lives either in the browser or in the org-file, never in both. This will allow us to not have to maintain so much state in the browser which has proven to be super hard to keep in sync. Browser creates a ton of events in rapid succession for tabs, which cause a lot of problems and need complex solutions to work around.

  Now that spookfox's CSP allow injecting JS into the background script itself, we should try to keep no state in browser. This will allow supporting multiple browsers and browser-windows; e.g archiving a set of tabs from one browser, and open in another.