Modify labels configuration for litmus-core

[Calvinaud]

• Create seperate set of labels/labelSelector for the operator and exporter
• Include the app label in the common label in helper.tpl
• Update the helper.tpl so the label management is closer to the sub-chart of litmus-agent (the selector label are included in the list of label)

What this PR does / why we need it:

Update the labels configuration so that the labels for operator and exporter are not the same. The goal was that the service doesn't match both the exporter and operator at the same time. Which is the setup in the chaos-exporter sub-chart of litmus-agent. I tried to match the configuration of the sub-chart of litmus-agent.

Which issue this PR fixes

(optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged)

• fixes #357

Checklist

[Place an '[x]' (no spaces) in all applicable fields. Please remove unrelated fields.]

• [X] DCO signed
• [X] Chart Version bumped
• [X] Variables are documented in the README.md

[v-vostretsov]

Hi guys any updates on this one?

[uditgaurav]

Hi @Calvinaud , Can you please update the version to fix conflicts.

[Calvinaud]

Hi @Calvinaud , Can you please update the version to fix conflicts.

Updated by bumping version to 3.7.1