This commit takes the `HybridVisitor` in the language service and gives it
the ability to return not just a node but the template context in which it
appears. In the future, more context regarding where a node appears in the
template might become necessary (ex: the microsyntax container for binding
nodes), and this refactoring enables that.
In the process, `HybridVisitor` is renamed and the concept of a
`TemplateTarget` interface is introduced to contain the results of this
operation.
PR Close#39505