[expo-manifests][expo-dev-launcher] add logUrl getter to manifest classes

[esamelson]

Why

resolves ENG-4080

How

Added logUrl getters to base manifest classes on both platforms, replaced usages from #15964 and #15938.

Test Plan

Made a build on each platform, and opened app using expo start --dev-client and expo start --dev-client --force-manifest-type=expo-updates, logged the new logUrl property on manifest to ensure it was nonnull and correct.

Was not able to verify that the actual logging functionality of the dev client still works; I tried to follow the test plans from #15964 and #15938 but did not figure out the right place to throw an exception (it either showed me a redbox or just showed the error as an alert in the dev launcher UI) to trigger the logging. I can try this out again if you could provide more details about how to test this!

Checklist

• Documentation is up to date to reflect these changes (eg: https://docs.expo.dev and README.md).
• This diff will work correctly for expo build (eg: updated @expo/xdl).
• This diff will work correctly for expo prebuild & EAS Build (eg: updated a module plugin).

[linear]

ENG-4080 add a getter for the `logUrl` to the manifest class instead of accessing the raw JSON

A follow up to the #15964 (comment)