Improve error reporting when trying to debug with kit that misses debugger

• set the debugger in a otherwise working kit to "No debugger"
• use one of the debugger actions to start debugging

Actual: A message "Unable to create a debugging engine." is printed to the output pane. In case of Android debugging there even is text before and after that making it hard to pinpoint this as the actual issue.

Expected: Either the debugging actions should be disabled in the first place (with a useful tool tip on the tool button(s)), or an error message appears that tells me that my Kit doesn't have a debugger and points me to the corresponding settings.