wwan: fix hide-disconnected default, plug dup() leaks, meson/man cleanup

- update(): only hide the module when hide-disconnected is set AND the
  modem is not in the CONNECTED state, instead of hiding it unconditionally
  (the module was invisible by default).
- free the gchar* returned by mm_modem_dup_physdev/
  mm_modem_dup_equipment_identifier/mm_sim_dup_operator_name.
- meson.build: drop duplicate libgps dependency, install the wwan man page.
- man: document hide-disconnected (replacing the unimplemented
  hide-failed/hide-disabled/hide-not-registered options).
- remove stray empty subprojects/.wraplock.

man/waybar-wwan.5.scd

@@ -113,20 +113,10 @@ libmm-glib lives in:
 	typeof: string ++
 	Select only the modem with the corresponding hardware path.
 
-*hide-failed*: ++
+*hide-disconnected*: ++
 	typeof: bool ++
 	default: true ++
-	Defines if the module should be hidden if the modem cannot start.
-
-*hide-disabled*: ++
-	typeof: bool ++
-	default: false ++
-	Defines if the module should be hidden if the modem is disabled.
-
-*hide-not-registered*: ++
-	typeof: bool ++
-	default: false ++
-	Defines if the module should be hidden if the modem isn't registered with any carrier network.
+	Defines if the module should be hidden while the modem does not have an active data connection.
 
 
 # FORMAT REPLACEMENTS