Fix trainer failure result handling with objective C tests

[jaysoffian]

Checklist

• I've run bundle exec rspec from the root directory to see all new and existing tests pass
• I've followed the fastlane code style and run bundle exec rubocop -a to ensure the code style is valid
• I see several green ci/circleci builds in the "All checks have passed" section of my PR (connect CircleCI to GitHub if not)
• I've read the Contribution Guidelines
• I've updated the documentation if necessary.
• I've added or updated relevant unit tests.

Motivation and Context

When trainer is parsing an xcresult bundle which contains test failures, it has an ActionTestMetadata object that is identified one way (by "identifier") and it's trying to find the corresponding TestFailureIssueSummary object that's identified another way (by testCaseName). These values are not the same, so in order to locate the correct TestFailureIssueSummary object it needs to transform the testCaseName in the same way that Xcode does when generating the ActionTestMetadata identifier. Exactly how to do this is undocumented, so folks have attempted to figure it out empirically.

Most recently, dda4007 ([trainer] fix issues where number of failures would always be zero (#21432), 2024-01-10) changed this transformation code in a way that fixed test names that contain spaces, but broke Objective-C test names.

Description

This commit fixes the regression caused by dda4007 with ObjC tests as follows:

1. It reverts the transformation behavior to how the code worked previously. Instead of "sanitizing" both the identifier and the test case name, it now keeps the identifier as is and "normalizes" the test case name. The test case name normalization has been moved into its own method which passes unit tests for ObjC, Swift, and tests with spaces.

2. It adds an ObjC xcresult bundle and unit test to prevent regressing parsing ObjC test names.

3. It refactors summaries_to_data so that if the corresponding test failure message cannot be located (but hopefully that won't happen anymore), we at least properly report that the test failed, but use the generic "unknown failure message" as the failure message.

See discussion on:

• [trainer] sanitize test case name and test identifier consistently when looking up test failures #21565
• [trainer] fix issues where number of failures would always be zero #21432

Testing Steps

I ran rubocop and rspec on the trainer code. It passes the existing tests as well as a new test I added to identify this issue and prevent regressions.

[jaysoffian]

Not sure why the "Execute tests on macOS (Xcode 15.3, Ruby 3.3) job fails, but it doesn't seem to have anything to do with this PR.