Implicit style lookup not working correctly when control is part of a template

### Description

Implicit style lookup not working correctly when control is part of a template.
That's because `FindImplicitStyleResource` sets a `boundaryElement` which causes implicit style lookup to bubble up to the `ContentPresenter` and immediately skip to App- and Theme-Resources.

There is a comment in the code stating:

> // For non-controls the implicit StyleResource lookup must stop at
// the templated parent. Look at task 25606 for further details.

I have no clue what's inside task 25606, but if that code there is really required the details should be added to the comment.

### Reproduction Steps

See repro
[StyleLookup.zip](https://github.com/dotnet/wpf/files/14468291/StyleLookup.zip)

### Expected behavior

Both TextBlock elements should have a green foreground.

### Actual behavior

The TextBlock generated by the ContentPresenter has a red foreground.
Regular TextBlock has a green foreground.

### Regression?

No

### Known Workarounds

A workaround will be shown in the commits fixing https://github.com/snoopwpf/snoopwpf/issues/397
But such workaround is not suitable for regular applications i think.

### Impact

_No response_

### Configuration

_No response_

### Other information

_No response_