Support number of retries option for Firestore transactions

[Lyokone]

Discussed in #9155

^{Originally posted by puf July 19, 2022}
The native SDKs for iOS, Android, Web, Unity and C++ now all support an option to specify the maximum number of retries for a Firestore transaction, before it gives up.

• https://firebase.google.com/support/release-notes/ios#9.2.0
• https://firebase.google.com/support/release-notes/android#2022-06-23
• https://firebase.google.com/support/release-notes/unity#9.2.0
• https://firebase.google.com/support/release-notes/cpp-relnotes#9.2.0

It'd be great if the Flutter bindings for this SDK would also add this option.