chore: minor internal refactors

[Marvin9]

As part of university course assignment, I have to perform refactor where possible.

Here is the list of commits and what kind of refactor was followed.

1. 926936b Extract Variable
   extracted non trivial boolean operations in condition block and put it in self explanatory named variable.

2. c6f0261 Decompose Conditional
   moved scenario checking condition in BasicMappingBuilder.build. Also used checkState

3. 58b6723 Extract Method
   moved header injection and verifying response status in its own methods from HttpAdminClient.safelyExecuteRequest

4. 2c05908 Extract Class
I noticed JsonSchemaVersion should not be in WireMock class and saw that this was mentioned in the PR. Feel free to enlighten me about the side-effects this change could result or any other suggestion.

References

I haven't created an issue but would be happy to create one as I want to implement some more refactors.

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[oleg-nenashev]

Hi. Thanks for the pull request. JsonSchemaVersion relocation, while reasonable semantically, will break binary compatibility of items depending on the WireMock Core API. I do not think it worth the effort to migrate, at least until there is a major breaking re-architecture towards WireMock 4

[Marvin9]

@oleg-nenashev Would you mind re-review it?

[oleg-nenashev]

Thanks, these refactorings are fine. They do not reduce the code side or remove duplication, but arguably they improve code readability and might be helpful in the future

[Marvin9]

@oleg-nenashev can you please take a look again?

[oleg-nenashev]

Will try to merge it over the weekend