feat: Add type+format mappings for go

We now register type+format mappings for the go generator so that types
like integer with format uint64 get mapped correctly.

Author: cbascom

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractGoCodegen.java

@@ -117,9 +117,27 @@ public AbstractGoCodegen() {
         instantiationTypes.put("map", "GoMap");*/
 
         typeMapping.clear();
+        typeMapping.put("integer+int8", "int8");
+        typeMapping.put("integer+uint8", "uint8");
+        typeMapping.put("integer+int16", "int16");
+        typeMapping.put("integer+uint16", "uint16");
         typeMapping.put("integer", "int32");
+        typeMapping.put("integer+int32", "int32");
+        typeMapping.put("integer+int64", "int64");
+        typeMapping.put("integer+uint32", "uint32");
+        typeMapping.put("integer+uint64", "uint64");
         typeMapping.put("long", "int64");
+        typeMapping.put("number+int8", "int8");
+        typeMapping.put("number+uint8", "uint8");
+        typeMapping.put("number+int16", "int16");
+        typeMapping.put("number+uint16", "uint16");
+        typeMapping.put("number+int32", "int32");
+        typeMapping.put("number+int64", "int64");
+        typeMapping.put("number+uint32", "uint32");
+        typeMapping.put("number+uint64", "uint64");
         typeMapping.put("number", "float32");
+        typeMapping.put("number+float32", "float32");
+        typeMapping.put("number+float64", "float64");
         typeMapping.put("float", "float32");
         typeMapping.put("double", "float64");
         typeMapping.put("decimal", "float64");