Support parsing of $or and $and conditions

[ivansenic]

As the first step towards the $or in the document service, we should support the parsing of the $or. The $or should have a array JSON value with one or more conditions.

We should also explicitly support the $and, although we already do support it as all the condition in the same JSON object level would be wrapped in the and.

Example:

{
   "fixed":{
      "$eq":1
   },
   "$or":[
      {
         "one":{
            "$eq":1
         }
      },
      {
         "two":{
            "$eq":2
         }
      },
      {
         "$and":[
            {
               "three":{
                  "$eq":3
               }
            },
            {
               "four":{
                  "$eq":4
               }
            }
         ]
      }
   ]
}

should resolve as AND(fixed=1, OR(one=1, two=2, AND(three=4, four=4)))