Update Updates.set to allow Bson value argument (#1493)

Improves the ergonomics of the Updates helper and keeps `$set` helpers inline with `$setOnInsert`.

JAVA-5620

Author: tyilo

driver-core/src/main/com/mongodb/client/model/Updates.java

@@ -66,6 +66,17 @@ public static Bson combine(final List<? extends Bson> updates) {
         return new CompositeUpdate(updates);
     }
 
+    /**
+     * Creates an update that sets the values for the document.
+     *
+     * @param value the value
+     * @return      the update
+     * @mongodb.driver.manual reference/operator/update/set/ $set
+     */
+    public static Bson set(final Bson value) {
+        return new SimpleBsonKeyValue("$set", value);
+    }
+
     /**
      * Creates an update that sets the value of the field with the given name to the given value.
      *

driver-core/src/test/unit/com/mongodb/client/model/UpdatesSpecification.groovy

@@ -174,6 +174,10 @@ class UpdatesSpecification extends Specification {
                                                                                                   }''')
     }
 
+    def 'should set document'() {
+        toBson(set(parse('{ a : 1, b: "two"}'))) == parse('{$set : {a: 1, b: "two"} }')
+    }
+
     def 'should create string representation for simple updates'() {
         expect:
         set('x', 1).toString() == 'Update{fieldName=\'x\', operator=\'$set\', value=1}'