Add ability to add additional labels to server pods

[peterklijn]

I would like to add the ability to add additional labels to consul-server pods, the same way annotations can be added.

At the company I work for, we use specific Kubernetes pod labels to tell Fluentd which Elasticsearch index should be used to send logs to. With this change I can the additional label :)

[hashicorp-cla]

All committers have signed the CLA.

[thisisnotashwin]

Thanks so much for the PR @peterklijn . I just had a few comments on it. I tested this out and it worked great 😄

[thisisnotashwin]

This is excellent. Thanks for your contribution @peterklijn !!

[thisisnotashwin]

Hey @peterklijn

I was going through some of our other templates and realized we can potentially use toYaml here to template in the values. This way instead of accepting a string, we could accept a yaml block.

extraLabels:
  label1: val
  label2: val

instead of

extraLabels: |
  "label1": "val"
  "label2": "val"

We have used toYaml in multiple places so it should hopefully be straightforward.
Sorry for requesting changes after approving it bud.

[peterklijn]

No problem @ashwin-venkatesh :)

I've updated the extraLabels to use a yaml block.

Additionally I've updated the annotations to also support a yaml block (it currently supports both a yaml block and a string which is documented as deprecated). Let me know if that's ok :)

[lkysow]

I think we should leave out the annotations as string deprecation from this PR and put it in a separate PR that does the deprecation across all places where annotations can be set so we don't have inconsistency across the chart between components.

[thisisnotashwin]

Thanks @peterklijn

[peterklijn]

Thanks for the review @ashwin-venkatesh and @lkysow,

I've removed the annotation change and rebased with upstream