[chore] Method that sorts Datapoint Slice by Attribute key

[BominRahmani]

Adds a method that allows Metrics Datapoint slices of Golden files to be sorted by their respective attribute key. This is in the efforts to bring Golden files 1 step closer to being more deterministic.

There is a test folder (sort-datapoint-slice) in golden/testdata that shows an example of what this accomplishes.

[djaglowski]

Please also regenerate all golden files so we can see what the expected change is.

[djaglowski]

Can we have some additional data points that exercise the sorting of attributes within a map? Further, can we have some that require comparison beyond the first key?

• a
• b, a
• c, b
• c, b, a
• c, a, d

[djaglowski]

You should be able to omit these fields for this test, as they only distract from the point of the test.

[BominRahmani]

Please also regenerate all golden files so we can see what the expected change is.

This is already all the changes when running the sort datapoint slice.

[djaglowski]

This is already all the changes when running the sort datapoint slice.

Ok, I suppose this makes sense because we generally want data points to have the same attribute keys.

Since this PR doesn't improve the golden files, I think it makes sense to extend it to cover resources and scopes, where I expect we'll see meaningful improvements.

For data points, I think a followup PR will make sense, which layers on sorting by value, since the values tend to be static or even enumerated.

[djaglowski]

Thanks @BominRahmani, @dehaansa!