Migrate to manifest v3

[jleedev]

May want to hold off on merging this until one of:

• January 2023: Chrome ceases to run MV2 extensions and CWS ceases to accept updates to MV2 extensions; or
• Some point in 2022: Firefox begins to run MV3 extensions (and presumably accepts MV3 extensions in their web store).

Otherwise will require maintaining both copies of the manifest.

[zekefarwell]

Ugh. Yeah I saw this news. Hoping to kick the can down the road and not think about it until absolutely necessary. Looks like that will be in a little under a year.

[zekefarwell]

Thanks for the update on this, @jleedev. Sounds slightly annoying and also reminds me that I should see if I can submit this extension for Safari as well.

Apparently the long-term state of things will be service workers in
Chrome and event pages in Mozilla, and service workers falling back to
event pages in Safari. Chrome 121 and Firefox 121 will tolerate the
presence of both, but prior versions will error.

Those versions will be LTS/ESR around mid-late 2024. Probably ought not
to merge this until then.

Reference:
https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/manifest.json/background#browser_support

It looks like the Chrome web store will still accept manifest v2 updates to this extension so I can push out an update to deal with #11 in the short term. However it looks like June is going to be the point where manifest v2 support finally gets pulled out of Chrome itself: https://developer.chrome.com/docs/extensions/develop/migrate/mv2-deprecation-timeline . Looks like Chome 122 and and Firefox 121 are both out now. Do you think it's still too soon to make the transition?