added jsonnet and grafanet into confgenerator code

[KalmanMeth]

As a step towards creating grafana dashboards in the Network Observability Operator, this PR adds into the confgenerator the steps of running jsonnet using the grafannet defined constructs to generate the grafana panels, accessible via a function call (instead of performing these operations externally and then reading additional files).
The grafannet files are embedded in the confgenerator code so that they will be accessible when we run this code from the operator.

[codecov-commenter]

Codecov Report

Merging #369 (cbadb19) into main (84428d1) will decrease coverage by 7.56%.
The diff coverage is 54.86%.

📣 This organization is not using Codecov’s GitHub App Integration. We recommend you install it so Codecov can continue to function properly for your repositories. Learn more

@@            Coverage Diff             @@
##             main     #369      +/-   ##
==========================================
- Coverage   69.23%   61.67%   -7.56%     
==========================================
  Files          88       91       +3     
  Lines        5204     5939     +735     
==========================================
+ Hits         3603     3663      +60     
- Misses       1382     2045     +663     
- Partials      219      231      +12     

Flag	Coverage Δ
unittests	61.67% <54.86%> (-7.56%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
cmd/confgenerator/main.go	0.00% <0.00%> (ø)
pkg/confgen/config.go	33.33% <ø> (ø)
pkg/confgen/confgen.go	47.82% <35.71%> (-1.39%)	⬇️
pkg/confgen/grafana_jsonnet.go	54.21% <58.16%> (+6.73%)	⬆️
pkg/pipeline/pipeline_builder.go	71.06% <0.00%> (-0.46%)	⬇️
pkg/config/config.go	63.33% <0.00%> (ø)
pkg/api/write_ipfix.go	0.00% <0.00%> (ø)
pkg/pipeline/write/write_ipfix.go	0.00% <0.00%> (ø)
hack/examples/ipfix-collector/ipfix-dump.go	0.00% <0.00%> (ø)

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

[openshift-ci]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
Once this PR has been reviewed and has the lgtm label, please ask for approval from kalmanmeth by writing /assign @kalmanmeth in a comment. For more information see the Kubernetes Code Review Process.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[ronensc]

We have the hack/generate-dashboards.sh script which is triggered by make dashboards.
This script downloads the jsonnet CLI and grafonnet-lib to ./bin
So we have 2 instances of grafonnet-lib. Can we consolidate the two?

[ronensc]

IIUC grafana/grafonnet-lib contains selected files from https://github.com/grafana/grafonnet-lib
I think we should write it somewhere and include the its version

[KalmanMeth]

Added a sentence in confGenerator.md. Note that the License is already included in the grafonnet-lib directory.

[ronensc]

+1 for breaking this function into smaller functions

[KalmanMeth]

So we have 2 instances of grafonnet-lib. Can we consolidate the two?
Yes, we should remove the script from hack once this PR is merged.