Feature Request. Show tooltip of value with both current/top and selected frame in stack

[robertlzj]

Because, there maybe many variables in frame. (And all frame is unfold by default #925 ) So, it's harder to find var-value on non-top frame from stack window than from code content directly (after select frame). And show both (current/top and selected frame) (or even more) context information would nice, for there is enough space free(trade space for time). And this avoid ambiguity or exclusiveness on user operate. (similar with #924 )