Add support for --api-versions flag for helm template

[kvaps]

This PR adds support for passing --api-versions to helm template command. Many charts containing lookup functions, which allow to check if Kubernetes cluster supports specific apiVersions https://helm.sh/docs/chart_template_guide/functions_and_pipelines/#using-the-lookup-function

[codecov-commenter]

Codecov Report

Merging #257 (c6695dc) into master (5508c45) will increase coverage by 0.01%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #257      +/-   ##
==========================================
+ Coverage   73.87%   73.88%   +0.01%     
==========================================
  Files          72       72              
  Lines        5015     5017       +2     
==========================================
+ Hits         3705     3707       +2     
  Misses       1101     1101              
  Partials      209      209              

Impacted Files	Coverage Δ
vm/internal/natives/helm.go	90.24% <100.00%> (+0.50%)	:arrow_up:

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[harsimranmaan]

@kvaps qbec know supports external datasources https://qbec.io/reference/jsonnet-external-data/. It is possible to use helm(or any other tool) in a generic way without requiring native functions. @gotwarlost maybe we should looking at dropping the expandHelmTemplate in a future release

[Andor]

@harsimranmaan since https://github.com/splunk/qbec/issues/286 function expandHelmTemplate might be considered as a stable one. Could you please merge this change?