Feature: Align report Reporter api with mutation-testing-elements

[nicojs]

Is your feature request related to a problem? Please describe.
When we first started with Stryker there was no mutation-testing-elements.

There is a lot of overlap with the mutation-testing-report-schema field names, but subtle differences. See differences below.

Stryker	mutation-testing-elements
MutantStatus.TimedOut	MutantStatus.Timeout
estimatedNetTime	duration
coveredByTests (boolean)	coveredBy (array, an empty array means not covered)
testFilter (array)	coveredBy
testFilter (undefined)	static (true/false)
runAllTests (boolean)	static (true/false)
errorMessage, ignoreReason	statusReason
nrOfTestsRan	testsCompleted
id (number)	id (string)

We also have a lot of types that represent a mutant in different states of execution:

• Mutant -- a mutant generated and placed, but coverage is not yet measured.
• MutantTestCoverage -- internal type in Stryker core. A mutant of which coverage is measured, ready to be tested.
• MatchedMutant -- Like MutantTestCoverage but it's reporter API equivalent.
• MutantResult -- The final state of a mutant.
• MutantResult (mutation testing elements) -- The final state of a mutant (mutation testing elements variant).

Describe the solution you'd like

End up with 3 interfaces of mutants: Mutant, MutantTestCoverage, MutantResult. All of them are based on the mutation testing elements naming scheme.

Describe alternatives you've considered

Additional context
This is a breaking change because it will hit the Reporter API.

[nicojs]

@Garethp please take a look as well, since you will be hit by this issue

[nicojs]

Closed with #2798