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

src/mesh/generated/meshtastic/portnums.pb.h

@@ -54,6 +54,8 @@ typedef enum _meshtastic_PortNum {
     /* Audio Payloads.
  Encapsulated codec2 packets. On 2.4 GHZ Bandwidths only for now */
     meshtastic_PortNum_AUDIO_APP = 9,
+    /* Payloads for clients with a network connection proxying MQTT pub/sub to the device */
+    meshtastic_PortNum_MQTT_CLIENT_PROXY_APP = 10,
     /* Provides a 'ping' service that replies to any packet it receives.
  Also serves as a small example module. */
     meshtastic_PortNum_REPLY_APP = 32,