Fix: Use Go Generics to Consolidate Subset functions

[FirePheonix]

• Improvement: use of generics consolidate the earlier subset functions

Description

subsetOfGroups, subsetOfPolicies, and subsetOfValues were three identical functions differing only in map value type.

A TODO had already existed since the code was written acknowledging the duplication, but noted the signatures "need to be different".

At the time, Go had no generics, so there was no clean way to unify them without losing type safety.

Go 1.18 introduced generics. This PR resolves the TODO by replacing all three functions with a single subsetOf[V any] function, letting the compiler infer the concrete type at each call site. ZERO behavior change - the logic is identical.
Now, 60 lines -> 10 lines of code

I have also added a new test case for partial error corresponding to the changes I've done.

[pfi79]

It seems you've hit some unit tests.

[FirePheonix]

hey @pfi79 ,
I have a feeling that the test failing is completely unrelated to my changes..
and that test is failing right now in this PR since there's a shared variable between somewhere..

it's the TestConcurrentCreateLedgerFromSnapshot

the tests are running for so long and then failing, it might even be a race condition.
maybe i;m wrong, lemme see..

[pfi79]

hey @pfi79 , I have a feeling that the test failing is completely unrelated to my changes.. and that test is failing right now in this PR since there's a shared variable between somewhere..

it's the TestConcurrentCreateLedgerFromSnapshot

the tests are running for so long and then failing, it might even be a race condition. maybe i;m wrong, lemme see..

1. You can run the tests in your own brunch.
2. You can also run them for main.

When your pipe turns green locally, I'm ready to consider it further. So far, I've restarted your pr pipe 7-8 times and so far everything is bad.

[FirePheonix]

hey @pfi79 , i ran the tests on my PR replica, on shubhammms#3.

I was earlier re running all jobs by commiting on it, that didn't work.
But then I started running individual jobs, and all succeeded on that PR.

Been trying to figure it out for a whole day..
I think it's a CI issue which is failing due to load on the CI workers, you can observe that in the attempts, they fail on different tests in different different attempts.

[FirePheonix]

It ran successfully on attempt 10.
then failed in the next 2 again.

[FirePheonix]

YES.
the current attempt passed all.