store: Implement metadata API limit in stores

[harry671003]

• I added CHANGELOG entry for this change.
• Change is not relevant to the end user.

Changes

This PR is part of #7575 and implements the metadata API limit in stores.

• The querier will now pass the limit parameter to the stores.
• The stores will return limited results back to querier.

Verification

• Added Unit tests and updated e2e tests.

[yeya24]

Do we think it is worth it to pass limit into strutil.MergeSlices and truncate there?

func MergeSlices(a ...[]string) []string {
	if len(a) == 0 {
		return nil
	}
	if len(a) == 1 {
		return a[0]
	}
	l := len(a) / 2
	return mergeTwoStringSlices(MergeSlices(a[:l]...), MergeSlices(a[l:]...))
}

For example, if the limit is < len(a) / 2, we can skip merging the second half of slice.

[yeya24]

But this is not a blocker, we can do it in further prs

[harry671003]

Thanks Ben. I can look into it. Since this PR has gotten too big, I prefer to do in a follow up PR. :)

[MichaHoffmann]

Lgtm!

[MichaHoffmann]

Can we add acceptance tests in a followup PR? Just to make sure that all store implementations support this

[yeya24]

Thanks! This looks good. Agree with @MichaHoffmann that we need to update acceptance test in next pr.