Improve sigdetails button and verify caching
* src/gpgoladdin.cpp (GpgolRibbonExtender::GetIDsOfNames): (GpgolRibbonExtender::Invoke): Handle new icon callback. (GetCustomUI_MIME): Use new icon callback. * src/mail.cpp (Mail::Mail): New members for state caching. Rename m_uid to m_uuid to avoid confusion with the valid uid. (Mail::~Mail): Use renamed variables. (Mail::get_mail_for_uuid): Renamed. (Mail::decrypt_verify): Use renamed functions. (Mail::parsing_done): Add some traces for a crash. (Mail::update_sigstate): New. Called once after parsing done. (Mail::get_valid_sig): Use cached values. (Mail::is_valid_sig): Use cached values. (Mail::set_uuid): Renamed. (Mail::get_signature_status): Fix isOpenPGP (Mail::get_signature_icon_id): New. Use for new icons. (Mail::get_sig_fpr): New. Used for launch details. * src/mail.h: Update accordingly. * src/parsecontroller.cpp (ParseController::parse): Add some traces for a crash. * src/ribbon-callbacks.cpp (get_mail_from_control): Use renamed functions. (HRESULT launch_cert_details): Launch kleopatra on details. (HRESULT get_sigstate_icon): Get the Icon of a signature. * src/ribbon-callbacks.h: Update accordingly.