Implement @mockable support

[the-pavels]

ZIO guidelines suggest using zio-macros to generate helper methods for service mocking.
It would be great to add hints in Intellij Idea for the generated code.

[alexvanolst]

I'll add support for this.

[c-solo]

HI, is there any progress? Estimation?

[timaliberdov]

HI, is there any progress? Estimation?

Hi, thank you for the reminder! I'll take a look. Hopefully, I'll be able to get to it this week.