Draft: Add macOS support

This MR contains Bindings.xcframework build manually from client repo, using the following script:

go mod tidy
rm -rf vendor/
go build ./...
go get golang.org/x/mobile/bind
go install golang.org/x/mobile/cmd/gomobile@latest
gomobile init
gomobile bind -target ios,iossimulator,macos gitlab.com/elixxir/client/bindings

go version go1.17.13 darwin/arm64

run-tests.sh

 #!/bin/sh
 set -e
+
+echo "\n\033[1;32m▶ Running tests on macOS...\033[0m"
+set -o pipefail && swift test 2>&1 | ./xcbeautify
+
+echo "\n\033[1;32m▶ Running tests on iOS Simulator...\033[0m"
 set -o pipefail && xcodebuild -scheme 'elixxir-dapps-sdk-swift-Package' -sdk iphonesimulator -destination 'platform=iOS Simulator,OS=15.5,name=iPhone 13' test | ./xcbeautify