Go support requirements

[alisevych]

Go support open questions.

1. Is it possible to generate tests to a test sources root or a separate package?

Additional information from docs on go testing package: https://pkg.go.dev/testing#pkg-overview

The test file can be in the same package as the one being tested, or in a corresponding package with the suffix "_test".
If the test file is in the same package, it may refer to unexported identifiers within the package...
If the file is in a separate "_test" package, the package being tested must be imported explicitly and only its exported identifiers may be used. This is known as "black box" testing.

So if we don't need to generate tests for unexported functions - tests could be placed in a separate package.

[alisevych]

@egiptipavel @Markoutte Please share your opinion