feat(analytics): allow custom event parameters for begin_checkout and purchase events

[Minishlink]

Description

Hello, Firebase Web SDK allows these extra params: begin_checkout, purchase.
Used the solution from a previous similar PR for screen_view events #5811
This is useful for easily tracking conversion rates depending on some parameters.

Release Summary

Allow custom event parameters for begin_checkout and purchase events

Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
  • Yes
• My change supports the following platforms;
  • Android
  • iOS
• My change includes tests;
  • e2e tests added or updated in packages/\*\*/e2e
  • jest tests added or updated in packages/\*\*/__tests__
• I have updated TypeScript types that are affected by my change.
• This is a breaking change;
  • Yes
  • No

Test Plan

• Tested on Android and iOS, visible in DebugView

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Name	Status	Preview	Comments	Updated (UTC)
react-native-firebase	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Apr 20, 2024 1:01pm

[mikehardy]

These look great - thanks especially for linking the prior PR for an easy comparison and the firebase-js-sdk types for easy reference to make sure we maintain compatibility, all much appreciated

[mikehardy]

I don't believe the test failures have anything to do with this PR, I'm struggling with them currently.
One of the Android ones (higher API) went green immediately which is a vote of confidence for the PR.
Low Android API is consistently failing at the moment, it definitely should not block anything.
iOS should have passed but has been flaky. I am re-running it just to see if it goes green, but it won't block merge

[mikehardy]

@Salakar last one I think - this one also potentially affects typings