RUMM-303 Logging sampling rate

[maciejburda]

What and why?

Adds capability of sampling logs. It was pointed out in the Github issue that this feature already exists in Android.

How?

Added implementation allows configuring sampling rate for logging both globally from configuration and locally for logger using builder.

Review checklist

• Feature or bugfix MUST have appropriate tests (unit, integration)
• Make sure each commit and the PR mention the Issue number or JIRA reference
• Add CHANGELOG entry for user facing changes

Custom CI job configuration (optional)

• Run unit tests
• Run integration tests
• Run smoke tests

[datadog-datadog-prod-us1]

Datadog Report

Branch report: maciey/RUMM-303-logging-sampling-rate
Commit report: ff4baf2

✅ dd-sdk-ios 0 Failed, 0 New Flaky, 1909 Passed, 0 Skipped, 4m 43.32s Wall Time

[maxep]

Thanks, @maciejburda 👏

It's great to be able to have a global sampling rate in Datadog.Configuration and be able to override that in any Logger instance 👍 Also, the tests and objc interface looks great!

I see 2 things:

1. We can align with other sampling rate and make it non-optional, it will simplify things.
2. The sampling rate should be applied to RemoteLogger only, but all log entries to the ConsoleLogger should print.

[ncreated]

Really well done 🏅👍 - all changes make sense and tests coverage is nice 👌.

I left few minor feedbacks, but I don't see major blockers. Good to go after addressing @maxep 's feedback 🚀.

[maciejburda]

@ncreated @maxep I addressed all the comments. Please give it another round 🙏

[ncreated]

Awesome 🚀 - looks good and reads easy 👍.

[maxep]

Looks great, thank you 👍