[3.0] ask_exec(): no longer skip exec events in hats
Instead of ignoring all exec events that happen in a hat/child profile, only disallow child exec. ix and px are valid options inside a hat and are now offered to the user.
(When the tools support nested child profiles one day, we can even allow child exec again.)
Backported from dfb6f90a / !1133 (merged) to match the 3.1 branch
For 3.0, this also needed backporting another commit:
Fix crash caused by ask_exec()
ask_exec still uses aa[profile][hat], therefore
- use full_profile when accessing hashlog
- correctly split the merged profile name to profile and hat
- avoid accidently initializing non-existing aa[profile][hat]
This fixes a regression from converting lots of code to use flat profile//hat array keys.
(cherry picked from commit 755b5d11)