Upgrade to Ember v4.12

[mukilane]

Basically, this PR will,

• [x] Handle this lookup fallback (Basically #209 )
• [x] Upgrade dependencies and devDependencies to support v4.x
• [x] Update ember-try targets to currently supported LTS (and additionally 3.28.x)
• [x] Update supported node version to 14 and above.
• [x] Setup Github Actions

[knownasilya]

You should be able to add a file to change the node version on netlify see https://docs.netlify.com/configure-builds/manage-dependencies/#node-js-and-javascript