Add static class names to UI elements for easier customization (#4421)

* Initial plan

* Add static class names to UI elements for easier customization

Co-authored-by: gabek <414923+gabek@users.noreply.github.com>

* Add unique DOM element IDs for easier customization targeting

Co-authored-by: gabek <414923+gabek@users.noreply.github.com>

* Remove duplicate class names, keep only IDs for UI element targeting

Co-authored-by: gabek <414923+gabek@users.noreply.github.com>

* Revert chat input field ID to original value

Co-authored-by: gabek <414923+gabek@users.noreply.github.com>

* Remove unnecessary nested spans and revert Button ID to original value

Co-authored-by: gabek <414923+gabek@users.noreply.github.com>

* Standardize ID names to follow owncast-{element-description}-{type} pattern

Co-authored-by: gabek <414923+gabek@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: gabek <414923+gabek@users.noreply.github.com>
Co-authored-by: Gabe Kangas <gabek@real-ity.com>

web/components/chat/ChatNameChangeMessage/ChatNameChangeMessage.tsx

@@ -27,7 +27,10 @@ export const ChatNameChangeMessage: FC<ChatNameChangeMessageProps> = ({ message
       </div>
       <div className={styles.nameChangeText}>
         <span style={{ color }}>{oldName}</span>
-        <span className={styles.plain}> is now known as </span>
+        <span className={styles.plain} id="owncast-name-change-is-now-known-text">
+          {' '}
+          is now known as{' '}
+        </span>
         <span style={{ color }}>{displayName}</span>
       </div>
     </div>