Improve the timestamp parsing

[einarmo]

Add a timestampwrapper config utility, which should make this type easier to use in a good way in config.

Make it accept RFC3339-like datetimes, but also shortened. We require a timezone, which IMO is a good idea, to avoid ambiguity.

[codecov]

Codecov Report

Attention: Patch coverage is 83.33333% with 7 lines in your changes missing coverage. Please review.

Project coverage is 78.21%. Comparing base (8b44bc4) to head (84f8e64).
Report is 2 commits behind head on master.

Files with missing lines	Patch %	Lines
Cognite.Config/TimestampWrapper.cs	69.56%	4 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #523      +/-   ##
==========================================
+ Coverage   78.10%   78.21%   +0.10%     
==========================================
  Files         123      125       +2     
  Lines       11541    11790     +249     
  Branches     1748     1785      +37     
==========================================
+ Hits         9014     9221     +207     
- Misses       1817     1833      +16     
- Partials      710      736      +26     

Files with missing lines	Coverage Δ
Cognite.Common/CogniteTime.cs	83.73% <100.00%> (+3.73%)	⬆️
Cognite.Config/YamlConfigBuilder.cs	81.13% <100.00%> (+0.11%)	⬆️
Cognite.Config/TimestampWrapper.cs	69.56% <69.56%> (ø)

... and 2 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[ozangoktan]

Looks great!

[finnag]

This deserves a little more thorough testing

[finnag]

That was an extremely simplified list of tests?

In a good old test driven methology the winning implementation would be return DateTime(2020, 1, 1, 0, 0, 0, DateTimeKind.Utc) to satisfy all tests.

We should at least test that it parses the numbers in the right order (day/month/year/hour/minute/), that time zones work as intended, that bad dates do NOT parse, and so on.

[einarmo]

I added some more test cases, but there really is only so much value in testing a standard library function.

[einarmo]

@finnag I've updated this, it's ready for another risk review.

Try fix list

[finnag]

🦄7