Replacing extensions hash code **breaking change**

This is a large update, I realized that extensions are not being hashed correctly, and because I have the same code everywhere, it means running back through the stack and cleaning up the invalid code that will break if multiple extensions are used in different positions in the raw spec.

At the same time, I realized that the v2 model has the same primitive/enum issues that are part cleaned up in v3. This is a breaking changhe because enums are now []any and not []string, as well as primitives for bool, int etc are all pointers now instead of the copied values.

This will break any consumers.

datamodel/low/base/schema_test.go

@@ -263,6 +263,28 @@ func TestSchema_Hash(t *testing.T) {
 
 }
 
+func BenchmarkSchema_Hash(b *testing.B) {
+
+	//create two versions
+	testSpec := test_get_schema_blob()
+	var sc1n yaml.Node
+	_ = yaml.Unmarshal([]byte(testSpec), &sc1n)
+	sch1 := Schema{}
+	_ = low.BuildModel(&sc1n, &sch1)
+	_ = sch1.Build(sc1n.Content[0], nil)
+
+	var sc2n yaml.Node
+	_ = yaml.Unmarshal([]byte(testSpec), &sc2n)
+	sch2 := Schema{}
+	_ = low.BuildModel(&sc2n, &sch2)
+	_ = sch2.Build(sc2n.Content[0], nil)
+
+	for i := 0; i < b.N; i++ {
+		assert.Equal(b, sch1.Hash(), sch2.Hash())
+	}
+
+}
+
 func Test_Schema_31(t *testing.T) {
 	testSpec := `$schema: https://something
 type:
@@ -1246,26 +1268,86 @@ func TestExtractSchema_OneOfRef(t *testing.T) {
 func TestSchema_Hash_Equal(t *testing.T) {
 
 	left := `schema:
+  $schema: https://athing.com
+  multipleOf: 1
+  maximum: 10
+  minimum: 1
+  maxLength: 10
+  minLength: 1
+  pattern: something
+  format: another
+  maxItems: 10
+  minItems: 1
+  uniqueItems: 1
+  maxProperties: 10
+  minProperties: 1
+  additionalProperties: anything
+  description: milky
+  contentEncoding: rubber shoes
+  contentMediaType: paper tiger
+  default:
+     type: jazz
+  nullable: true
+  readOnly: true
+  writeOnly: true
+  deprecated: true
+  exclusiveMaximum: 23
+  exclusiveMinimum: 10
+  type:
+    - int
+  x-coffee: black
+  enum:
+    - one
+    - two
+  x-toast: burned
   title: an OK message
   required:
     - propA
-  enum:
-    - one
   properties:
     propA:
       title: a proxy property
       type: string`
 
 	right := `schema:
+  $schema: https://athing.com
+  multipleOf: 1
+  maximum: 10
+  x-coffee: black
+  minimum: 1
+  maxLength: 10
+  minLength: 1
+  pattern: something
+  format: another
+  maxItems: 10
+  minItems: 1
+  uniqueItems: 1
+  maxProperties: 10
+  minProperties: 1
+  additionalProperties: anything
+  description: milky
+  contentEncoding: rubber shoes
+  contentMediaType: paper tiger
+  default:
+     type: jazz
+  nullable: true
+  readOnly: true
+  writeOnly: true
+  deprecated: true
+  exclusiveMaximum: 23
+  exclusiveMinimum: 10
+  type:
+    - int
   enum:
     - one
+    - two
+  x-toast: burned
   title: an OK message
+  required:
+    - propA
   properties:
     propA:
       title: a proxy property
-      type: string
-  required:
-    - propA`
+      type: string`
 
 	var lNode, rNode yaml.Node
 	_ = yaml.Unmarshal([]byte(left), &lNode)