Adds a userPrefs.h file, default blank, used for default settings for custom builds (#4325)

* add a userPrefs.h file, default blank, which can be used to easily set defaults on custom builds.

* Add Splash Screen to userPrefs

* Add channel 0 defaults to userPrefs.h

* CONFIG_LORA_IGNORE_MQTT_DEFAULT

* Unify naming for USERPREFS defines

---------

Co-authored-by: Ben Meadors <benmmeadors@gmail.com>

src/mesh/NodeDB.cpp

@@ -1,3 +1,4 @@
+#include "../userPrefs.h"
 #include "configuration.h"
 #if !MESHTASTIC_EXCLUDE_GPS
 #include "GPS.h"
@@ -237,10 +238,22 @@ void NodeDB::installDefaultConfig()
     config.lora.tx_enabled =
         true; // FIXME: maybe false in the future, and setting region to enable it. (unset region forces it off)
     config.lora.override_duty_cycle = false;
+#ifdef CONFIG_LORA_REGION_USERPREFS
+    config.lora.region = CONFIG_LORA_REGION_USERPREFS;
+#else
     config.lora.region = meshtastic_Config_LoRaConfig_RegionCode_UNSET;
+#endif
+#ifdef LORACONFIG_MODEM_PRESET_USERPREFS
+    config.lora.modem_preset = LORACONFIG_MODEM_PRESET_USERPREFS;
+#else
     config.lora.modem_preset = meshtastic_Config_LoRaConfig_ModemPreset_LONG_FAST;
+#endif
     config.lora.hop_limit = HOP_RELIABLE;
+#ifdef CONFIG_LORA_IGNORE_MQTT_USERPREFS
+    config.lora.ignore_mqtt = CONFIG_LORA_IGNORE_MQTT_USERPREFS;
+#else
     config.lora.ignore_mqtt = false;
+#endif
 #ifdef PIN_GPS_EN
     config.position.gps_en_gpio = PIN_GPS_EN;
 #endif