feat: custom text for user displayname suffix upon registration

replaces the lightning bolt emoji option with support for
your own text or emojis

Signed-off-by: strawberry <strawberry@puppygock.gay>

src/service/admin/mod.rs

@@ -647,9 +647,11 @@ impl Service {
                     // Default to pretty displayname
                     let mut displayname = user_id.localpart().to_owned();
 
-                    // If enabled append lightning bolt to display name (default true)
-                    if services().globals.enable_lightning_bolt() {
-                        displayname.push_str(" ⚡️");
+                    // If `new_user_displayname_suffix` is set, registration will push whatever content is set to the user's display name with a space before it
+                    if !services().globals.new_user_displayname_suffix().is_empty() {
+                        displayname.push_str(
+                            &(" ".to_owned() + services().globals.new_user_displayname_suffix()),
+                        );
                     }
 
                     services()