SPM wrapper for GoogleAnalytics library

It's just a xcframework downloaded from podspec link and Package.swift file with target declaration. Temporary solution until Google makes it available from the box.

How to update library

1. Open GoogleAnalytics podspec list in CocoaPods repo: https://github.com/CocoaPods/Specs/tree/master/Specs/4/9/c/GoogleAnalytics
2. Open the target version folder (for example 3.21.0)
3. Open the podspec file and find the source object
4. Download archive following the link in source object
5. Replace old xcframework in repo with new xcframework from archive
6. Push changes to the repository
7. Update swift package in Xcode

Inspired by:

• https://github.com/pimms/google-analytics-spm
• https://github.com/kammodze/google-analytics-ios-spm