feat: Full Text Search Support (#3904)

* Full Text Support

* invalid input test

* Support for sort

* index exist test

* clean up

* better error messaging

* postgres support

* error instructions for $diacritic and $case sensitivity

* nit

* nit

* nit

* separate test for full text

src/RestQuery.js

@@ -94,7 +94,9 @@ function RestQuery(config, auth, className, restWhere = {}, restOptions = {}, cl
       var fields = restOptions.order.split(',');
       this.findOptions.sort = fields.reduce((sortMap, field) => {
         field = field.trim();
-        if (field[0] == '-') {
+        if (field === '$score') {
+          sortMap.score = {$meta: 'textScore'};
+        } else if (field[0] == '-') {
           sortMap[field.slice(1)] = -1;
         } else {
           sortMap[field] = 1;