Move benchmark tests between ValidGen and GoValidator to another repository

[alexgarzao]

The motivation for moving to another repository is to clean up the mod file from GoValidator imports.

[leocavalcante]

This issue asks to move the ValidGen vs GoValidator benchmark tests into another repository so go.mod can drop github.com/go-playground/validator/v10.

The destination repository is not named. I am not creating a public repository or guessing a name. A directory or nested module in this repository would not meet the request, because the request is a different repository.

The comparison code that imports the validator is:

• tests/bench/validator_test.go
• tests/cmpbenchtests/generated_cmp_perf_no_pointer_test.go
• tests/cmpbenchtests/generated_cmp_perf_pointer_test.go
• testgen/cmp_perf_no_pointer_tests.tpl
• testgen/cmp_perf_pointer_tests.tpl

Moving only those files would still leave an import in types/color_test.go (TestColorMatchesValidator). That test checks color compatibility and is not a benchmark comparison, so the root module would still require the validator.

Needed decision: the destination repository URL or owner/name for these benchmark tests.

[leocavalcante]

The destination is https://github.com/opencodeco/validgen-benchmarks.

#118 moves the comparison benchmarks there. TestColorMatchesValidator moves with them, because that test was the other import of github.com/go-playground/validator/v10. After that pull request, the ValidGen module does not require that package.

TestGen writes cmp/generated_cmp_perf_*.go when VALIDGEN_BENCHMARKS_DIR points at a checkout of the benchmarks repository.