Require authentication to participate in chat (#4762)

* feat(chat): require authentication to participate in chat

* fix: it's pretty much impossible to bypass the auth requirement, addressing review feedback anyway

* feat(chat): render chat text input as disabled if chat auth is required

* Commit updated API documentation

---------

Co-authored-by: Owncast <owncast@owncast.online>

web/utils/config-constants.tsx

@@ -40,6 +40,7 @@ const API_CHAT_JOIN_MESSAGES_ENABLED = '/chat/joinmessagesenabled';
 const API_CHAT_ESTABLISHED_MODE = '/chat/establishedusermode';
 const API_CHAT_SPAM_PROTECTION_ENABLED = '/chat/spamprotectionenabled';
 const API_CHAT_SLUR_FILTER_ENABLED = '/chat/slurfilterenabled';
+const API_CHAT_REQUIRE_AUTHENTICATION = '/chat/requireauthentication';
 const API_DISABLE_SEARCH_INDEXING = '/disablesearchindexing';
 const API_SOCKET_HOST_OVERRIDE = '/sockethostoverride';
 const API_VIDEO_SERVING_ENDPOINT = '/videoservingendpoint';
@@ -292,6 +293,14 @@ export const CHAT_ESTABLISHED_USER_MODE = {
   useSubmit: true,
 };
 
+export const FIELD_PROPS_CHAT_REQUIRE_AUTHENTICATION = {
+  apiPath: API_CHAT_REQUIRE_AUTHENTICATION,
+  configPath: '',
+  label: 'Require Authentication',
+  tip: 'Only users who have authenticated may chat.',
+  useSubmit: true,
+};
+
 export const TEXTFIELD_PROPS_CHAT_FORBIDDEN_USERNAMES = {
   apiPath: API_CHAT_FORBIDDEN_USERNAMES,
   placeholder: 'username',