Add resolve submodule conflict dialog

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Refactored: Move conflict resolve code to CAppUtils

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Allow to resolve submodule conflicts and update list

Signed-off-by: Sven Strickroth <email@cs-ware.de>