Add support for extra arguments for falcosidekick chart

[ogercyprien]

What type of PR is this?
/kind feature
/kind chart-release

Any specific area of the project related to this PR?
/area falcosidekick-chart

What this PR does / why we need it:
This PR add support for extra args for falcosidekick chart. This allows specifying a config file for falcosidekick for situations when relying on environment variables is not possible (e.g. settings which contain confidential values which are injected into a file).
This is useful when secrets are loaded into pods with Hashicorp Vault's Agent sidecar injector.

A possible usage in falco's values.yaml file is:

falcosidekick:
  enabled: true 
  config:
    extraArgs:
      - -c
      - /a/b/c/config.yaml

This loads the config.yaml file located at /a/b/c/config.yaml for falcosidekick.

Which issue(s) this PR fixes:
No issue is opened for this PR

Special notes for your reviewer:
I've bumped the falcosidekick chart version to 0.7.7 and the falco chart to 3.8.3 (to update the referenced falcosidekick version).

Checklist

• Chart Version bumped
• Variables are documented in the README.md
• CHANGELOG.md updated

[poiana]

Welcome @ogercyprien! It looks like this is your first PR to falcosecurity/charts 🎉

[Issif]

You can't update all the charts in the same PR, can you scope to falcosidekick only please

[ogercyprien]

You can't update all the charts in the same PR, can you scope to falcosidekick only please

Sure, I've remove the changes to the Falco chart, I can make another PR after this one to update Falco to target Falcosidekick v0.7.7.
Is the current PR better for you now?

[poiana]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: Issif, ogercyprien

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[poiana]

LGTM label has been added.

Git tree hash: 1caeb378e7585c062b7a7f32f56d4e8b06c04cec