feat: add IsValidIndex

[mojixcoder]

Additions:

• C.isValidIndex

Fix:

• Return ErrFailed instead of ErrUnknown which is not a standard error code in H3

  The H3 library may always add additional error messages. Error messages not recognized by the application should be treated as E_FAILED.

Upgrades:

• Upgrade h3 to v4.4.1

[mojixcoder]

I also upgraded to v4.4.1, but after running the update script nothing changed.

[mojixcoder]

Can someone run tests please?

[coveralls]

Pull Request Test Coverage Report for Build 20011070865

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 4 of 4 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 100.0%

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Totals
Change from base Build 19321058736:	0.0%
Covered Lines:	786
Relevant Lines:	786

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💛 - Coveralls

[mojixcoder]

Fixed coverage issue.

[mojixcoder]

lint was complaining about IsValidIndex not having comments, so I added comments to this method.

[zachcoleman]

lgtm