MQTT client proxying (#2587)

* WIP on MQTT proxy message queue

* Fix copy paste goof

* Progress on uplink

* Has packets

* Avoid trying to connect if we're proxying

* Pointer correctly

* Remove wifi guards

* Client proxy subscribe

* Fixed method that got bababababorked somehow... personally I blame CoPilot

* Short circuit logic

* Remove canned settings

* Missed some stuff in the move

* Guard pubsub client for non-networked variants

* Has networking guard

* else

* Return statement for fall-thru

* More gaurd removals

* Removed source filters. No wonder I was confused

* Bounding

* Scope guard around else and fix return

* Portduino

* Defs instead

* Move macro up to actually fix portduino

* Size_t

* Unsigned int

* Thread interval

* Protos

* Protobufs ref

arch/nrf52/nrf52.ini

@@ -9,7 +9,7 @@ build_flags =
   -Isrc/platform/nrf52
 
 build_src_filter = 
-  ${arduino_base.build_src_filter} -<platform/esp32/> -<platform/stm32wl> -<nimble/> -<mesh/api/> -<mesh/http/> -<modules/esp32> -<mqtt/> -<platform/rp2040> -<mesh/eth/>
+  ${arduino_base.build_src_filter} -<platform/esp32/> -<platform/stm32wl> -<nimble/> -<mesh/api/> -<mesh/http/> -<modules/esp32> -<platform/rp2040> -<mesh/eth/>
 
 lib_deps=
   ${arduino_base.lib_deps}