Missing presets.json on factory reset bugfix.

Clarification on loading ledmaps in UI.
Added manual ledmap loading.

wled00/fcn_declare.h

@@ -195,6 +195,7 @@ void handlePlaylist();
 void serializePlaylist(JsonObject obj);
 
 //presets.cpp
+void initPresetsFile();
 void handlePresets();
 bool applyPreset(byte index, byte callMode = CALL_MODE_DIRECT_CHANGE);
 inline bool applyTemporaryPreset() {return applyPreset(255);};