Support backtick phrase queries in Streaming Expressions

Currently in order to make phrase queries in Streaming Expressions you must escape the quotes as follows:

search(collection1, q="fieldA:\"hello world\" AND fieldB:two")

This ticket will allow phrase queries to be entered with back ticks as follows:

search(collection1, q="fieldA:`hello world` AND fieldB:two") 

Back ticks are nice because they are infrequently searched on and people in the SQL world are used to back ticks meaning "take the literal value of this string".

Under the covers back ticks will be translated to double quotes.