Add type constraints for Map and Array fields

[hanzei]

Summary

By adding type constraints for Map and Array fields, it's ensured at compile time that no non-array or non-map is passed to these methods.

This is the first introduction of generics in this codebase. I hope it's allowed.

Ticket Link

None

[github-actions]

Unit Test Results

71 tests  +2   71 ✔️ +2   24s ⏱️ ±0s
10 suites ±0     0 💤 ±0 
  1 files   ±0     0 ❌ ±0 

Results for commit 07edba1. ± Comparison against base commit e0a61b2.

♻️ This comment has been updated with latest results.

[wiggin77]

@hanzei normally an API signature change would be a breaking change requiring a major version bump. I think this is closer to something like changing interface{} to any. The only exception being any case where a non-map or slice is currently passed which won't compile now.

Thoughts on whether we need a full version bump? I've not worked much with generics in Go yet.

[hanzei]

I've added a couple of tests in 289a135 and 07edba1 to ensure the code complies with any combination I could think of. Yes, existing code will fail to compile with a non-map or non-slice type.

Error caused by the changes in this PR are "good" errors IMO.

[hanzei]

@wiggin77 Can we merge this PR?