feat: Update CRD to add Volume and ConfigTemplate

[Fei-Guo]

Reason for Change:
This change removes hostPath field in DataSource and DataDestination struct. Instead, a standard K8s VolumeSource API is used to specify the volumes used by the tuning Job. This will provide the highest flexibility for users to load/store the data. HostPath field is hard to use in practice.

This change also renames the Config to ConfigTemplate because the final configmap used by the tuning job will be generated by the controller based on the template. The new name is clearer.

Notes for Reviewers:
We will revisit how to do validation check for the Volume field because it is a fairly complicated API.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 30.76923% with 9 lines in your changes are missing coverage. Please review.

Project coverage is 62.39%. Comparing base (fde6369) to head (e83ea67).
Report is 6 commits behind head on main.

Files	Patch %	Lines
api/v1alpha1/zz_generated.deepcopy.go	0.00%	9 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #356      +/-   ##
==========================================
- Coverage   62.89%   62.39%   -0.50%     
==========================================
  Files          14       14              
  Lines        1307     1311       +4     
==========================================
- Hits          822      818       -4     
- Misses        447      455       +8     
  Partials       38       38              

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