Formats full crash reports with extra diagnostic information

[matux]

Description of the change

This formatter will generate a valid Apple crash report version 104 using the extended diagnostic information generated by our diagnostics filter.

+9000 lines correspond to a crash reports used in unit tests. Another ~200 to Xcode related project files such as schemes, hopefully knowing this makes the PR less scary.

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RollbarCrashFormattingFilter class is our hook into KSCrash report post-crash processing that happens the next time the app is opened after a crash occurred, and before sending the report to Rollbar.

The formatting occurs after the RollbarCrashDiagnosticFilter is done extracting all the extra diagnostic information we use.

The entry point is the filterReports function. We receive an array of reports, each report is a hashmap (a Dictionary in Apple parlance), that we validate for correctness and then format by producing by making use of an internal micro-DSL that helps us format the report with which must simplicity, we then send back the report as an NSString to the KSCrash processing pipeline, where we eventually receive it and send it to Rollbar.

Diagnostic/RollbarCrashFormattingFilter.swift would be a good place to start a review.

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The formatter uses a mini-DSL created for the purpose of building complex multiline strings in a simple, straightforward way, the DSL is defined in FormatBuilder.swift.

Files in the Report dir correspond to the data structures in the json report. Not all objects in the json structure have a defined data struct.

Type of change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Maintenance
• New release

Related issues

Shortcut stories and GitHub issues (delete irrelevant)

• Finishes 121447

Checklists

Development

• Lint rules pass locally
• The code changed/added as part of this pull request has been covered with tests
• All tests related to the changed code pass in development

Code review

• This pull request has a descriptive title and information useful to a reviewer. There may be a screenshot or screencast attached
• "Ready for review" label attached to the PR and reviewers assigned
• Issue from task tracker has a link to this pull request
• Changes have been reviewed by at least one other engineer

[tarsolya]

@matux It was a long time ago when I was working with Swift the last time, so I can't attest to the language "correctness", but the the functionality and the new format of crash reports with the additional diag info was pretty straightforward to understand for me.

I defer back to you (or someone else with more up to date swift exp) on language / swift specific technicalities.

[matux]

@tarsolya Much appreciated!