fix(store): fix traversed returning duplicate values

[otonashixav]

Fixes #840

Also made the type of traversed reflect the keys traversed e.g. Will make a PR after the other store type PRs are done

setStore("list", [0, 1], (v, traversed) => {
  traversed[0]; // <-- number
  traversed[1]; // <-- "list"
})

[coveralls]

Pull Request Test Coverage Report for Build 1819805147

• 3 of 3 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.004%) to 89.447%

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Totals
Change from base Build 1811033532:	-0.004%
Covered Lines:	1201
Relevant Lines:	1282

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💛 - Coveralls

[otonashixav]

I left #824 in this by accident, going to just keep it to fixing traversed and leave the types to later

Edit: done

[ryansolid]

Thanks. Looks good.