[Feature Request] Dump crash file for a crashing test into JUnit failure node

[benasher44]

When a test crashes, trainer outputs something about how the test crashed into the failure node (i.e. whatever is picked up from the TestSummaries.plist). Sometimes this has what the main thread was doing when the test crashed; sometimes it just says the test crashed. When a test crashes, the .crash files are available in the xcresult bundle as an "attachment." Inside of the TestSummaries.plist, attachments that belong to a given test are listed for each test. It would be great if trainer would take advantage of this to make richer results when a test crashes, by dumping the contents of the .crash file into the failure node (maybe after a nice horizontal separator to separate crash info from test output).

With this improvement, you could get the full crash details without having to download the xcresult bundle from your CI environment and dig through the .crash files yourself (as well as pair the .crash files to their tests yourself).