feat: add IsZero method to UUID, UUIDs, NullUUID

[osamingo]

Implementing IsZero() bool method would also support the omitzero option for JSON marshalling to omit zero UUID.

[bgrant0607]

@noahdietz I see you contributed to this repo. Do you know who could review this PR?

[bgrant0607]

Another PR for this feature: #167.

[noahdietz]

@noahdietz I see you contributed to this repo. Do you know who could review this PR?

Hello hello @bgrant0607 , we (@quartzmo and I) will look into this !

[bgrant0607]

Hello hello. Thanks much @noahdietz

[osamingo]

@noahdietz @quartzmo Hi, I have a request regarding for code review of this PR.

In order to comply with new Go specs, we'd greatly appreciate it if you could proceed with this code review.

Please, if possible would be greatly appreciated. thank you.

[bgrant0607]

Ref #113

[brunql]

Hello any news?

[bgrant0607]

This repo has had no changes in over a year, so my guess is that it has been de-prioritized.

https://github.com/google/uuid/graphs/contributors?from=6%2F28%2F2025
https://www.reddit.com/r/golang/comments/1kmh4cc/is_githubcomgoogleuuid_abandoned/