Introduce a struct DebuggerItem as a debugger configuration
item, containing debugger engine type and binary. Store
information as a variant map. Add a combo box.

Remove engine guessing logic. Parts of it are still required
when checking the suggested debugger from the SDK.

Split error checking to be able to do a quick error check
and find only valid profiles in the matchers.

Pass on errors up to RunControl::create().

Change-Id: I08653e2a76ca2c371701082f8173b0b8f8ed462e
Reviewed-by: Tobias Hunger <tobias.hunger@nokia.com>