Add user-agent-string-switcher

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

hosts/common/configs/user/gui/firefox/default.nix

@@ -75,6 +75,7 @@ in
                       "_446900e4-71c2-419f-a6a7-df9c091e268b_-browser-action"
                       "_aecec67f-0d10-4fa7-b7c7-609a2db280cf_-browser-action"
                       "languagetool-webextension_languagetool_org-browser-action"
+                      "_a6c4a591-f1b2-4f03-b3ff-767e5bedf4e7_-browser-action"
                     ];
                     "nav-bar" = [
                       "sidebar-button"
@@ -109,6 +110,8 @@ in
                     "sponsorblocker_ajay_app-browser-action"
                     "_73a6fe31-595d-460b-a920-fcc0f8843232_-browser-action"
                     "developer-button"
+                    "_a6c4a591-f1b2-4f03-b3ff-767e5bedf4e7_-browser-action"
+                    "screenshot-button"
                   ];
                   "dirtyAreaCache" = [
                     "unified-extensions-area"
@@ -139,6 +142,7 @@ in
           ublock-origin
           violentmonkey
           wayback-machine
+          user-agent-string-switcher
         ];
 
         search = {