Addon native classes

[maxwondercorn]

Decorators (tagName, classNamesBindings, etc) remain because outer HTML breaks demo app/tests due to the extra divs. Using @tagName('') to remove them causes other errors.

I believe everything needs to be converted to glimmer to finish the cleanup.

addObserver, removeObserver are used instead of the @observes decorator because it's not glimmer compatible

[vstefanovic97]

@maxwondercorn , @rwwagner90. Do you have a plan or currently work in progress to convert this to glimmer?
I would like to help in the effort to update this addon.
Not sure if you want to convert everything in one go or do you think it is a better idea to just create incremental PRs upgrading parts until we have covered everything?

[RobbieTheWagner]

@vstefanovic97 we would love the help! I think either way is fine.

[RobbieTheWagner]

I think we need to take another look at what should be @tracked and make sure all the things are updating as we expect. Alternatively, we could put back some of the old computeds.

[maxwondercorn]

I think we need to take another look at what should be @tracked and make sure all the things are updating as we expect. Alternatively, we could put back some of the old computeds.

Added computed back. Most properties are on the class which still need to be converted to native classes

[RobbieTheWagner]

@maxwondercorn I totally forgot about this PR, sorry about that! Where did we leave off?