Faktor out golden tests into separate test suite in wire-api.

[fisx]

This pulls the combined test suite in wire-api apart and makes it two suites that can be run and compiled separately to save time. To get the previous experience:

stack test --fast wire-api

To only run (and, more importantly, compile) the test suite that you need:

stack test --fast wire-api:wire-api-tests
stack test --fast wire-api:wire-api-golden-tests

Checklist

• The PR Title explains the impact of the change.
• The PR description provides context as to why the change should occur and what the code contributes to that effect. This could also be a link to a JIRA ticket or a Github issue, if there is one.
• changelog.d contains the following bits of information:
  • A file with the changelog entry in one or more suitable sub-sections. The sub-sections are marked by directories inside changelog.d.

[fisx]

I think cabal test wire-api:wire-api-tests also does the trick.

[battermann]

LGTM