fix a lot of low level cppcheck warnings (#9623)

* simplify the observer pattern, since all the called functions are const getters.
* use arduino macro over std: for numerical values and refactor local variables in drawScrollbar()
* oh, so Cppcheck actually complained about const pointers not being const.
* slowly getting out of ifdef hell
* fix inkHUD warnings as well
* last 2 check warnings
* git checks should fail on low defects from now on

src/modules/Telemetry/Sensor/SEN5XSensor.h

@@ -114,7 +114,7 @@ See: https://sensirion.com/resource/application_note/low_power_mode/sen5x
     bool sendCommand(uint16_t command);
     bool sendCommand(uint16_t command, uint8_t *buffer, uint8_t byteNumber = 0);
     uint8_t readBuffer(uint8_t *buffer, uint8_t byteNumber); // Return number of bytes received
-    uint8_t sen5xCRC(uint8_t *buffer);
+    uint8_t sen5xCRC(const uint8_t *buffer);
     bool startCleaning();
     uint8_t getMeasurements();
     // bool readRawValues();