🔥 feat(utils): add IsZeroValue

[sixcolors]

Description

Add utils function to support change to #2751

Adds IsZeroValue function to utils pkg. Which reports whether x is the zero value for its type. For basic types and error, it uses a fast path without reflection. For other types, it uses reflection which is slower.

Type of change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• If new dependencies exist, I have checked that they are really necessary and agreed with the maintainers/community (we want to have as few dependencies as possible)
• I tried to make my code as fast as possible with as few allocations as possible
• For new code I have written benchmarks so that they can be analyzed and improved

[sixcolors]

basic types based on https://go.dev/tour/basics/11

[gaby]

@sixcolors Probably worth comparing your implementation with this one: https://github.com/duke-git/lancet/blob/main/validator/validator.go#L390

Unit-Tests here: https://github.com/duke-git/lancet/blob/main/validator/validator_test.go#L413

Lancet is used by over +1k repos, so it's worth comparing.

[sixcolors]

Set to draft while considering if related change is appropriate or not

[sixcolors]

As @nickajacks1 pointed out #2751 (comment) a IsZeroValue check for ContextKeys would cause issues for some types that could be valid keys. So I’m closing this PR.