Debugger: Reimplement #10671.
- Rather than the previous (reverted) approach of tracking the last selected
stack frame from within the StackTraceView, we now do so from the TeamWindow,
where the selection can be mapped by thread. This fixes a subtle issue where,
due to a lack of contextual information, the stack trace view would restore
the remembered last selected frame rather than an explicitly chosen one. This
was most noticeable upon selecting a function that had a corresponding stack
frame in the current stack trace, where, instead of selecting that frame,
the existing one would remain highlighted, even though the state of all other
views had updated. Found while investigating the cause of #13710.