Switch from ZIP 32 account indices to UUID account identifiers

[str4d]

This PR is opened against main as a draft solely so it can be pre-reviewed. Once #1632 is complete and merged, I'll rebase this branch and then retarget it against a feature branch (so we can review and merge it before the backing Rust changes are released).

Closes #1633.

Author

• [ ] Self-review your own code in GitHub's web interface[^1]
• [ ] Add automated tests as appropriate
• [ ] Update the manual tests[^2] as appropriate
• [ ] Check the code coverage[^3] report for the automated tests
• [ ] Update documentation as appropriate (e.g README.md, Architecture.md, etc.)
• [ ] Run the demo app and try the changes
• [ ] Pull in the latest changes from the main branch and squash your commits before assigning a reviewer[^4]

Reviewer

• [ ] Check the code with the Code Review Guidelines checklist
• [ ] Perform an ad hoc review[^5]
• [ ] Review the automated tests
• [ ] Review the manual tests
• [ ] Review the documentation, README.md, Architecture.md, etc. as appropriate
• [ ] Run the demo app and try the changes[^6]

[^1]: Code often looks different when reviewing the diff in a browser, making it easier to spot potential bugs. [^2]: While we aim for automated testing of the SDK, some aspects require manual testing. If you had to manually test something during development of this pull request, write those steps down. [^3]: _While we are not looking for perfect coverage, the tool can point out potential cases that have been missed. Code coverage can be generated with: ./gradlew check for Kotlin modules and ./gradlew connectedCheck -PIS_ANDROID_INSTRUMENTATION_TEST_COVERAGE_ENABLED=true for Android modules._ [^4]: Having your code up to date and squashed will make it easier for others to review. Use best judgement when squashing commits, as some changes (such as refactoring) might be easier to review as a separate commit. [^5]: In addition to a first pass using the code review guidelines, do a second pass using your best judgement and experience which may identify additional questions or comments. Research shows that code review is most effective when done in multiple passes, where reviewers look for different things through each pass. [^6]: While the CI server runs the demo app to look for build failures or crashes, humans running the demo app are more likely to notice unexpected log messages, UI inconsistencies, or bad output data. Perform this step last, after verifying the code changes are safe to run locally.

[str4d]

Force-pushed to rebase on main afer #1641 was merged.