lay groundwork for a possible future architecture (#1571)

* lay groundwork for a possible future architecture

* switch from feature opt-out to feature opt-in

* lay groundwork for a possible future architecture

* switch from feature opt-out to feature opt-in

* fix USE_RTC in variant.h for rak4631_epaper and t-echo

* ensure Screen.h is not included without configuration.h

Co-authored-by: Peter Lawrence <12226419+majbthrd@users.noreply.github.com>
Co-authored-by: Ben Meadors <benmmeadors@gmail.com>

src/mesh/http/ContentHandler.cpp

@@ -14,7 +14,7 @@
 #include <HTTPURLEncodedBodyParser.hpp>
 #include <json11.hpp>
 
-#ifndef NO_ESP32
+#ifdef ARCH_ESP32
 #include "esp_task_wdt.h"
 #endif
 
@@ -787,7 +787,7 @@ void handleBlinkLED(HTTPRequest *req, HTTPResponse *res)
             count = count - 1;
         }
     } else {
-#ifndef NO_SCREEN
+#if HAS_SCREEN
         screen->blink();
 #endif
     }