Hardware pin defaults in i2c and spi pin dropdowns

bugfix: replace oappend(SET_F(name)); by oappend(_name);

const.h: remove unset of 8266 variables as no behind the scene actions, this is just bad behavior and the pin drop downs will show this bad behavior

xml.cpp: show hardware defaults as ⍼ in dropdowns (better icon needed)

usermods/usermod_v2_auto_save/usermod_v2_auto_save.h

@@ -205,7 +205,7 @@ class AutoSaveUsermod : public Usermod {
     }
 
     void appendConfigData() {
-      oappend(SET_F("addHB('")); oappend(SET_F(_name)); oappend("');");
+      oappend(SET_F("addHB('")); oappend(_name); oappend("');");
     }
 
     /*