To keep the breakpoint state machinery simple

Remove BreakHandler::hasPendingBreakpoints, handle new types
in CDB and gdb. Start fixing Breakpoint-Dialog.
Add assignment of Breakpointresponse from BreakpointParameters.

Reviewed-by: hjk

For Breakpoint data manipulation.

Reviewed-by: hjk

FIXME: add translations once interface has stabilized.

It also shows the response data.

The breakpoints are now (fairly) tightly guarded by the BreakpointHandler.
Engines and Views are only supposed to refer to them by id. They also have
individual states now. The breakpoint data is split into a "user requested"
"fixed" part in BreakpointData and the engines' acknowledged data in a new
struct BreakpointResponse.

TODO: Move m_state and m_engine members to BreakpointResponse. Fix regressions
in the marker handling.

There's  some 'external' and some 'internal' part now. Other plugins
are only supposed the external interface.