Correctly wire up hierarchical injectors for downgraded components in
`upgrade/static`: Downgraded components inherit the injector of the first
downgraded component up the DOM tree.
This is similar to (part of) d91a86a, but for `upgrade/static`.
POSSIBLE BREAKING CHANGE:
In order to enable more control over the wiring of downgraded components and
their content (which eventually allows better control over features like
injector setup and content projection), it was necessary to change the
implementation of the directives generated for downgraed components.
The directives are now terminal and manually take care of projecting and
compiling their contents in the post-linking function. This is similar to how
the dynamic version of `upgrade` does it.
This is not expected to affect apps, since the relative order of individual
operations is preserved. Still, it is difficult to predict how every possible
usecase may be affected.
1367cd9569