feat: Allow environment variables in run configurations

[blorente]

Checklist

• I have filed an issue about this change and discussed potential changes with the maintainers.
• I have received the approval from the maintainers to make this change.
• This is not a stylistic, refactoring, or cleanup change. (Well, a little bit)

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Discussion thread for this change

Issue Number: #2042
Replaces #4138

Description of this change

Allow users to set their own env vars per run-configuration. It is not respected everywhere (see the list below), but it works on our example projects.

Main features:

• Env vars should work when runing and debugging any binary.
• Env vars should work when running any test.
• Env vars should work when debugging Go and Java tests (and probably Kotlin because it delegates to the Java runner, but I couldn't test it). Env vars for C++ test debugging are implemented internally, but they're part of a larger patch and I'll need some more work to untangle that (or maybe they're already covered in Pass environment variables from BlazeCidrLauncher down to bazel #5771)
• Macro expansions (e.g. $WorkspacePath$) are not supported in Debug mode.

This work was based off of @victoriaroseb 's initial implementation.

[blorente]

This looks like a smallish change, but it's in a deep part of the codebase. I've tested it locally on the workflows listed, but please do give it a shot. It can use as many eyes as we can give it.

[mai93]

I manually tested it for Java, it is not working when running a single test method but works when running the whole test class. I also think we need to also add unit tests.

[blorente]

@mai93 Thanks for the comments! I've tried to address the inline ones there, but for the broader points:

I manually tested it for Java, it is not working when running a single test method but works when running the whole test class.

I've found that it works on a single method just fine (as long as I add the env vars to the new config as well). I've added example run configurations to the greetings_project to demonstrate, but please let me know if you still see that.

I also think we need to also add unit tests

I haven't done this yet, but will look into where it makes sense to add them. Thanks!

[blorente]

I have added a few unit tests, particularly for java tests. Unfortunately, I haven't seen any unit or integration tests for the biggest changes (namely, how the processes are actually spawned).
Please let me know if you'd like me to add more tests somewhere else.

[mai93]

I left small comments and I tested it manually on Java, it is working fine. Thanks @blorente!

[mai93]

Sorry if I misunderstood it, but in the PR description it says that Env vars should work for go debugging. has this changed?

[blorente]

I should have written a better comment, sorry about that.
The main issue is that, because of how we pass env vars to debuggers, the IntelliJ macros (e.g. $ProjectName$) are not expanded. So, the env vars get passed, but the macros don't get expanded.

I've added a new run configuration to test env vars, which works on both run and debug.

[blorente]

@mai93 Thanks for the review! Comments addressed, please take a look when you have time.

[mai93]

Thanks @blorente! LGTM, leaving the merge for you if you want someone else to take a look as well.

[blorente]

Given the amount of time this has been active internally I'm pretty confident of merging after your review, but I'm happy to work on fixing issues (or writing documentation about where env vars do and don't work).