Solr datasource is been added - Feature REVIEW

[varadekd]

• Issue: [Link to the issue. Do not use any of the github automation keywords]
  SOLR datasource #34

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Enter a brief description of the PR contents here
We have added a new datasource which is solr, this is added by creating a new query adapter that converts the es query to the solr based query. The main objective behind this PR is to share the code with @richard-jones and get the understanding that this is exactly what we discussed and this is the agreed style of our code.

Developer Checklist

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• Code meets acceptance criteria from issue
• Sufficient testing has been carried out
• Project's coding standards are met link
• Code documentation and related non-code documentation has all been updated

Reviewer Checklist

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If there are multiple reviewers, this section can be duplicated for each reviewer

• Code meets acceptance criteria from issue
• Sufficient testing has been carried out
• Project's coding standards are met link
• Code documentation and related non-code documentation has all been updated

Testing

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