Added GeoClue2 privacy item

Rebased onto current master and fixed the privacy module build:
- privacy_item.hpp no longer includes privacy.hpp (it does not use the
  Privacy class); this broke the circular include that left PrivacyItem
  undeclared when privacy.hpp was reached first from privacy_item.cpp.
- privacy_item.cpp now includes gtkmm/label.h explicitly, since Gtk::Label
  was previously only pulled in transitively via privacy.hpp.

man/waybar-privacy.5.scd

@@ -28,7 +28,7 @@ the screen or playing audio.
 
 *modules* ++
 	typeof: array of objects ++
-	default: [{"type": "screenshare"}, {"type": "audio-in"}] ++
+	default: [{"type": "screenshare"}, {"type": "audio-in"}, {"type": "location"}] ++
 	Which privacy modules to monitor. See *MODULES CONFIGURATION* for++
 	more information.
 
@@ -52,9 +52,13 @@ the screen or playing audio.
 
 *type*: ++
 	typeof: string ++
-	values: "screenshare", "audio-in", "audio-out" ++
+	values: "screenshare", "audio-in", "audio-out", "location" ++
 	Specifies which module to use and configure.
 
+*icon-name*: ++
+	typeof: string ++
+	If set, changes the modules icon.
+
 *tooltip*: ++
 	typeof: bool ++
 	default: true ++
@@ -95,6 +99,10 @@ the screen or playing audio.
 			"type": "audio-in",
 			"tooltip": true,
 			"tooltip-icon-size": 24
+		},
+		{
+			"type": "location",
+			"icon-name": "location-services-active-symbolic"
 		}
 	],
 	"ignore-monitor": true,
@@ -118,3 +126,4 @@ the screen or playing audio.
 - *#privacy-item.screenshare*
 - *#privacy-item.audio-in*
 - *#privacy-item.audio-out*
+- *#privacy-item.location*