[BUG] qt-client missing qHash and operator== for schemes with unique models

Created by: Thaulino

Bug Report Checklist

How to reproduce ?
Have you provided a full/minimal spec to reproduce the issue?
Have you validated the input using an OpenAPI validator (example)?
Have you tested with the latest master to confirm the issue still exists?
Have you searched for related issues/PRs?
What's the actual output vs expected output?
[Optional] Sponsorship to speed up the bug fix or feature request (example)

First of all: Props to all contributors and thanks for the openapi-generator 😃

Description

The generated code produced by the qt-client generator does not compile, if a scheme is included which includes lists of unique items.

openapi-generator version

5.2.0
openapi-generator-cli-6.0.0-20211025.061654-22.jar (newest ?)

OpenAPI declaration file content or url

https://app.swaggerhub.com/apis/Pepperl-Fuchs/Sensorik4.0/1.0.0#/common.identification.identification_1

alternative: www.pepperl-fuchs.com/openapi -> click on Pepperl+Fuchs Sensorik4.0® will be redirected

The issue is rooted in the SCHEMAS:

common.identification.identification
common.identification.identification_1

which include sets of unique objects.

Generation Details

Unsure what i should enter here: i am using vcpkg, c++, CMake and qt,
platform: win10
ide: vs2019

Steps to reproduce

Install dependencies

If you are using vcpkg: My vcpkg.json

{
	"name": "openapisensorik40",
	"version-string" : "1.0",
	"description": "project to implement the openapisensorik40",
	"dependencies": [
		"qt5-base",
		"openssl"
	]
}

Download the mentioned oai specification
Run open-api-generator
Run Cmake to configure and build the library

An error is thrown, something like:

qHash: none of the 37 overloads could convert argument types for OAICommon_identification_identification_1 OAICommon_identification_identification

Related issues/PRs

None?

Suggest a fix

From my point of view the issue is cause in some missing definition in order to make qhash(needed by QSet ) with a custom class work:
Refer: https://doc.qt.io/qt-5/qhash.html#qhash

I fixxed the issue by adding an operator== and a hash function to the classes.

Wihtin OAICommon_identification_identification_1.h: Add following function/ properties: to OAICommon_identification_identification_1 Within class definition (public)

bool operator==(const OAICommon_identification_identification_1& other) const {  
    return (this->asJsonObject() == other.asJsonObject());  
}

End of file prior #endif

inline uint qHash(const OpenAPI::OAICommon_identification_identification_1& obj, uint seed = 0)
{
    return qHash(obj.asJsonObject(), seed);
}

Wihtin OAICommon_identification_identification_2.h: Add following function/ properties: to OAICommon_identification_identification_2 Within class definition (public)

bool operator==(const OAICommon_identification_identification_2& other) const {  
    return (this->asJsonObject() == other.asJsonObject());  
}

End of file prior #endif

inline uint qHash(const OpenAPI::OAICommon_identification_identification_2& obj, uint seed = 0)
{
    return qHash(obj.asJsonObject(), seed);
}

Well i think it is possible to add this to the corresponding mustache file, but right now i am pretty unsure where to start and if it is enough or need some additional coding.

Can someone advice ?