New file editor (#4956)

- no mendatory external JS dependency, works in offline mode
- optional external dependency is used for highlighting JSON, plain text edit is used if not available
- WLED styling (dark mode only)
- JSON files are displayed "prettyfied" and saved "minified"
- JSON color highlighting (if available)
- JSON verification during edit and on saving both in online and offline mode
- special treatment for ledmap files: displayed in aligned columns (2D) or as lines (1D), saved as minified json: no more white-space problems
- displays file size and total flash usage

wled00/wled.cpp

@@ -167,7 +167,6 @@ void WLED::loop()
   // 15min PIN time-out
   if (strlen(settingsPIN)>0 && correctPIN && millis() - lastEditTime > PIN_TIMEOUT) {
     correctPIN = false;
-    createEditHandler(false);
   }
 
   // reconnect WiFi to clear stale allocations if heap gets too low