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/platform/esp32/MeshtasticOTA.cpp

@@ -75,7 +75,7 @@ bool getAppDesc(const esp_partition_t *part, esp_app_desc_t *app_desc)
     return true;
 }
 
-bool checkOTACapability(esp_app_desc_t *app_desc, uint8_t method)
+bool checkOTACapability(const esp_app_desc_t *app_desc, uint8_t method)
 {
     // Combined loader supports all (both) transports, BLE and WiFi
     if (strcmp(app_desc->project_name, combinedAppProjectName) == 0) {

src/platform/esp32/MeshtasticOTA.h

@@ -16,7 +16,7 @@ void initialize();
 bool isUpdated();
 const esp_partition_t *getAppPartition();
 bool getAppDesc(const esp_partition_t *part, esp_app_desc_t *app_desc);
-bool checkOTACapability(esp_app_desc_t *app_desc, uint8_t method);
+bool checkOTACapability(const esp_app_desc_t *app_desc, uint8_t method);
 void recoverConfig(meshtastic_Config_NetworkConfig *network);
 void saveConfig(meshtastic_Config_NetworkConfig *network, meshtastic_OTAMode method, uint8_t *ota_hash);
 bool trySwitchToOTA();