This is extracted from #8094, where I have run into some snags. Since
these ESLint fixes aren’t actually connected to the Ember 3.16 update
but involve changes to many files, we might as well address them
separately. Where possible I fixed the problems but in cases where
a fix seemed too involved, I added per-line or -file exceptions.
This is mostly deprecation fixes and blueprint changes. There
are some dependency updates too; the changes to Ember
Basic Dropdown necessitated changing it to angle bracket
component invocation. The conversion of the rest of the
templates will happen separately.
Since DOM code is in a run.next, it's possible that between the DOM
code being queued and running the element is destroyed. So the DOM
code needs to guard against this using the isDestroyed API.
