Make solr references in the Collection & Alias CRDs more flexible.

[HoustonPutman]

Right now both accept a cloud in the form of a string. This is meant to be the name of a solrCloud resource in the same namespace as the collection/alias resource referencing it.

We should make these more flexible, like the PrometheusExporter CRD.

So something like:

spec:
  solr:
    kubeSolr:
      name: test
      namespace: test
    cloudUrl: test.com:8983/solr
    zkConnectionInformation:
      connectionString: test1:2181,test2:2181
      chRoot: /test

All of these options would be optional, and would have defaults. But one of kubeSolr, cloudUrl or zkConnectionInformation (names not set in stone) would have to be specified.

[HoustonPutman]

The SolrCollection and SolrCollectionAlias CRDs are no longer supported by the Solr Operator.