[POC] Testable iOS Core with proxy

[louiszawadzki]

What does this PR do?

Expose the data from the iOS proxy core and create some assertions on them.

Motivation

Make E2E tests less dependent on upload mechanism.

Additional Notes

This is a POC that it works, the following improvements should be made:

Extract DdCoreTests from the RN SDK into a dedicated package

• to avoid packing it into the SDK

Improvements to the tests:

• Create simple interfaces for the events so it’s easier to make assertions
• Run all the tests and then gather then in a test report
• have only one screen at the end displaying the report status and report id
• upload the report as a log so it can be debugged more easily than on a phone

Improve error messages:

• present similar events available
• if length of events does not match, print all received events

Make a function for getting Actions, Long Tasks, Resources, etc. instead of one for all RUM events

More scenarios to be added to the tests:

• Resources (custom + auto-instrumentation)
• Actions (custom + auto-instrumentation)
• JS Crashes (we can add an error handler discarding it to prevent from crashing the app)
• Headers for first-party hosts

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests
• Make sure you discussed the feature or bugfix with the maintaining team in an Issue
• Make sure each commit and the PR mention the Issue number (cf the CONTRIBUTING doc)
• If this PR is auto-generated, please make sure also to manually update the code related to the change