Add Thanos Query frontend in Query CRD and deployment

[saswatamcode]

This adds Thanos Query frontend within query crd, which generates cache config if you don't specify

[saswatamcode]

Based on discussion offline with @philipgough I think it makes sense to combine with the Query CRD directly. Will update PR

[saswatamcode]

Modified this to be a nested field on Query CRD, but have kept the builder code separate as it is a separate thanos component and not a mode of another.