Chart: custom labels for extrasecrets/configmaps

[Aakcht]

This PR allows users to specify custom labels for secrets/configmaps created with extraSecrets/extraConfigMaps params

---

^ Add meaningful description above

Read the Pull Request Guidelines for more information.
In case of fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
In case of a new dependency, check compliance with the ASF 3rd Party License Policy.
In case of backwards incompatible changes please leave a note in a newsfragment file, named {pr_number}.significant.rst or {issue_number}.significant.rst, in newsfragments.

[Aakcht]

Looks like the failing checks are not related to this PR so I won't retrigger the test runs.

[potiuk]

LGTM @jedcunningham @ephraimbuddy @dstandish ?

[Aakcht]

@jedcunningham please take a look, I removed description and moved default up a level, though I had to make an exception for extraconfigmap/secrets in values_schema.schema.json .

[jedcunningham]

Looks good, a little unfortunate the conditional is tied to the description but I didn't come up with anything better yesterday when I hacked on it a bit either.