[Nexus][PVR] Timer settings dialog: Set certain settings to default on change of timer type.

[ksooo]

Backport of #23384

@emveepee fyi

@phunkyfish whenever you find some time for the code review

[ksooo]

Jenkins errors are unrelated.

00:21:33.831 C:\jenkins-workspace\workspace\WIN-UWP-32\kodi-build.win32-uwp\build\cores\RetroPlayer\messages\savestate_generated.h(12,46): error C2338: static_assert failed: 'Non-compatible flatbuffers version included' (compiling source file C:\jenkins-workspace\workspace\WIN-UWP-32\xbmc\cores\RetroPlayer\savestates\SavestateFlatBuffer.cpp) [C:\jenkins-workspace\workspace\WIN-UWP-32\kodi-build.win32-uwp\libkodi.vcxproj]
00:21:34.001 C:\jenkins-workspace\workspace\WIN-UWP-32\kodi-build.win32-uwp\build\cores\RetroPlayer\messages\video_generated.h(12,46): error C2338: static_assert failed: 'Non-compatible flatbuffers version included' (compiling source file C:\jenkins-workspace\workspace\WIN-UWP-32\xbmc\cores\RetroPlayer\savestates\SavestateFlatBuffer.cpp) [C:\jenkins-workspace\workspace\WIN-UWP-32\kodi-build.win32-uwp\libkodi.vcxproj]
00:21:34.095 C:\jenkins-workspace\workspace\WIN-UWP-32\kodi-build.win32-uwp\build\cores\RetroPlayer\messages\savestate_generated.h(151,12): error C2672: 'flatbuffers::Table::VerifyField': no matching overloaded function found (compiling source file C:\jenkins-workspace\workspace\WIN-UWP-32\xbmc\cores\RetroPlayer\savestates\SavestateFlatBuffer.cpp) [C:\jenkins-workspace\workspace\WIN-UWP-32\kodi-build.win32-uwp\libkodi.vcxproj]