Add server url button to main menu (#15536)

Co-authored-by: Zughy <63455151+Zughy@users.noreply.github.com>

LICENSE.txt

@@ -63,6 +63,7 @@ Zughy:
   textures/base/pack/settings_btn.png
   textures/base/pack/settings_info.png
   textures/base/pack/settings_reset.png
+  textures/base/pack/server_url.png
   textures/base/pack/server_view_clients.png
 
 appgurueu:

builtin/mainmenu/tab_online.lua

@@ -179,6 +179,13 @@ local function get_formspec(tabview, name, tabdata)
 				"server_view_clients.png") .. ";btn_view_clients;]"
 		end
 
+		if selected_server.url then
+			retval = retval .. "tooltip[btn_server_url;" .. fgettext("Open server website") .. "]"
+			retval = retval .. "style[btn_server_url;padding=6]"
+			retval = retval .. "image_button[" .. (can_view_clients_list and "4" or "4.5") .. ",1.3;0.5,0.5;" ..
+				core.formspec_escape(defaulttexturedir .. "server_url.png") .. ";btn_server_url;]"
+		end
+
 		if is_selected_fav() then
 			retval = retval .. "tooltip[btn_delete_favorite;" .. fgettext("Remove favorite") .. "]"
 			retval = retval .. "style[btn_delete_favorite;padding=6]"
@@ -367,6 +374,11 @@ local function main_button_handler(tabview, fields, name, tabdata)
 		return true
 	end
 
+	if fields.btn_server_url then
+		core.open_url_dialog(find_selected_server().url)
+		return true
+	end
+
 	if fields.btn_view_clients then
 		local dlg = create_clientslist_dialog(find_selected_server())
 		dlg:set_parent(tabview)