RUMM-494 Add milliseconds precision on iOS 11.0 and 11.1

[ncreated]

What and why?

📦 To mitigate production impact of #126 we sacrificed the millisecond precision on iOS11.0 and 11.1, as the ISO8601DateFormatter is buggy in those versions of the OS. This PR makes sure the precision is correct on all supported iOS versions (iOS 11+).

How?

The #available(iOS 11.2, *) check is used to produce different DateFormaterType implementations for date encoding:

• ISO8601DateFormatter for iOS11.2+,
• DateFormatter for iOS11.0 and iOS11.1.

Other things done in this PR

Time zone fix for .printLogsToConsole(_:usingFormat:.short)

I also noticed that #96 introduced a bug for .printLogsToConsole(true, usingFormat: .short) feature, as we no longer consider the timeZone argument for time formatting:

In result, all the dates were formatted with UTC timezone:

It was not possible to use ISO8601DateFormatter for console logs formatting, as it doesn't provide necessary format options to hide the time zone information, producing either:

11:00:00.001+01:00

for UTC+1, or:

10:00:00.001Z

for UTC. That's why the DateFormatter API is used for user-facing dates formatting.

Fixing tests execution on iOS 11.1 and iOS 12.4

In order to test the fix, I had to make tests execution on major iOS versions stable. That's why there are few fixes added. I made sure, both unit and integration tests run green on: 11.1, 12.4 and 13.5 Simulators. With RUMM-486 we will further ensure we execute them on daily basis for all supported OS versions.

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

[buranmert]

lack of timezone in presentation was a good catch 👏