Solr does not allow unquoted JSON DSL in query template

[mattoscln]

When including JSON DSL in a Solr query template, it must be quoted or is not added to the query correctly.

To Reproduce
Steps to reproduce the behavior:

1. Add a JSON parameter to a Solr query template:

{
  "json": {
    "query": {
      "lucene": {
        "query": "$query"
      }
    }
  }
}

2. Run the evaluation process.
3. Observe that the query details have not been added to the SolrQuery (eg. the query request looks like /select?fl=field1 field2&json=&rows=20

Expected behavior
Included JSON DSL should not require quotes around the content - this will make it harder to write and increase the number of potential bugs in the query where JSON is in use.

[agazzarini]

Closed with #79