fix: screen sharing on wayland; add:safeeyes

this did not work due to a missing/wrong implementation of pipewire
and xdg-portal. Now screensharing works in Microsoft Teams, Firefox as
well as Discord.

This also adds the safeeyes service.

profiles/common/nixos/xdg-portal.nix

@@ -0,0 +1,19 @@
+{ pkgs, ... }:
+{
+
+  xdg.portal = {
+    enable = true;
+    config = {
+      common = {
+        default = "wlr";
+      };
+    };
+    wlr.enable = true;
+    wlr.settings.screencast = {
+      output_name = "eDP-1";
+      chooser_type = "simple";
+      chooser_cmd = "${pkgs.slurp}/bin/slurp -f %o -or";
+    };
+  };
+
+}