Feature to show FIR/IR/bytecode diff between each phase for the compiler tests.

It would be significantly easier to onboard new employees and to find the bug source (as well as to use agents for those who use them).

It would be even greater if it was possible to compare the outputs for different versions of compiler etc.
The best option for that would be to provide the outputs of the different compilers in the txt formats and give a way to copy them.

It can be done with `-Xdump-...` options but:
* It is not trivial if the test uses several modules, files, reflection, etc.
* It requires getting distracted from the test infrastructure to temp projects with the manual option specifying and duplication.