UI: Add functions to check for and request macOS permissions

Adds functions to check and/or request specific macOS permissions
(audio device access, video device access, accessibility access, and
screen capture access).

By default only audio capture, video capture, and accessibility are
requested on launch - the first two have straight-forward "Yes/No"
prompts, the latter requires people to enable OBS in the settings
application (but is required for hotkey functionality, independent
of scene setups).

UI/obs-app.cpp

@@ -2185,6 +2185,15 @@ static int run_program(fstream &logFile, int argc, char *argv[])
 		}
 
 #ifdef __APPLE__
+		MacPermissionStatus audio_permission =
+			CheckPermission(kAudioDeviceAccess);
+		MacPermissionStatus video_permission =
+			CheckPermission(kVideoDeviceAccess);
+		MacPermissionStatus accessibility_permission =
+			CheckPermission(kAccessibility);
+		MacPermissionStatus screen_permission =
+			CheckPermission(kScreenCapture);
+
 		bool rosettaTranslated = os_get_emulation_status();
 		blog(LOG_INFO, "Rosetta translation used: %s",
 		     rosettaTranslated ? "true" : "false");