Extract the generated protobufs into its own Swift package

This change modifies the process for generating and integrating the Meshtastic protobufs into the client application.

* The generated Swift code is now in a local SPM package `MeshtasticProtobufs`
* An Xcode Workspace file `Meshtastic.xcworkspace` was created to more easily manage the new build targets.
* The code generation script for the protos was modified to generate the Swift code into the new location.
* The README.md was updated to reflect these changes.

NOTE: After merging this PR, do not open the project file `Meshtastic.xcodeproj`. You must use the workspace `Meshtastic.xcworkspace`

Extracting out the generated protobuf code into its own library enables several opportunities for the project. This is just a first step, but with some more modularization, a standalone Apple Watch app or other targets starts to become a little bit more achievable to implement.

After extracting the protobufs into a Swift package, I validate these changes by building and running the Meshtastic app to an iPhone 15 Pro Max, and tried changing some settings on a local node. I then messaged back and forth using two local nodes connected to two different iOS devices.

scripts/gen_protos.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+# simple sanity checking for repo
+if [ ! -d "./protobufs" ]; then
+   echo 'Please check out the protobuf submodule by running: `git submodule update --init`'
+  exit
+fi
+
+# simple sanity checking for executable
+if [ ! -x "$(which protoc)" ]; then
+  echo 'Please install swift-protobuf by running: `brew install swift-protobuf`'
+  exit
+fi
+
+protoc --proto_path=./protobufs --swift_opt=Visibility=Public --swift_out=./MeshtasticProtobufs/Sources ./protobufs/meshtastic/*.proto 
+
+echo "Done generating the swift files from the proto files."
+echo "Build, test, and commit changes."

scripts/thebenternify.sh

@@ -0,0 +1,4 @@
+#!/bin/bash
+
+sed -i '' -e 's/GCH7VS5Y9R/6YF6QJH524/g' ./Meshtastic.xcodeproj/project.pbxproj
+sed -i '' -e 's/gvh.Meshtastic/thebentern.Meshtastic/g' ./Meshtastic.xcodeproj/project.pbxproj

scripts/unthebenternify.sh

@@ -0,0 +1,4 @@
+#!/bin/bash
+
+sed -i '' -e 's/6YF6QJH524/GCH7VS5Y9R/g' ./Meshtastic.xcodeproj/project.pbxproj
+sed -i '' -e 's/thebentern.Meshtastic/gvh.Meshtastic/g' ./Meshtastic.xcodeproj/project.pbxproj