CC-874 migrate some components over to polaris

[libmartinito]

Checklist:

• I've thoroughly self-reviewed my changes
• I've added tests for my changes, unless they affect admin-only areas (or are otherwise not worth testing)
• I've verified any visual changes using Percy (add a commit with [percy] in the message to trigger)

[linear]

CC-874 Start using .gts files

Let's start using Ember's new "template imports" format: https://github.com/ember-template-imports/ember-template-imports.

Test it out on 2-3 small components to start with, and note any issues that we run into.

[libmartinito]

updated just before the base template. not sure how that would look like.

for effort to update: around 5 to 10 mins to convert and test as it's mostly just copy and paste per component. it only takes longer if there are broken imports.

[rohitpaulk]

updated just before the base template. not sure how that would look like.

@libmartinito what do you mean by "base template" here?

[rohitpaulk]

Okay so one major problem I'm noticing here is that there's no syntax highlighting for .gts files, which is a bummer - looks like https://github.com/github-linguist/linguist/pull/6578/files added support for .gjs but not .gts? We can wait for a while to see if this naturally resolves, and if not we'll contribute support ourselves. Issue: ember-cli/ember-template-imports#123

[libmartinito]

updated just before the base template. not sure how that would look like.

@libmartinito what do you mean by "base template" here?

i guess i should just say templates haha. templates receive data from controllers which in turn get their data from the route model. if i convert a template to a .gts file, does it mean that i get access to the route model directly and the controller goes away? maybe i could play around with that the next series of component migrations to polaris