[cpp-qt][client] add support for primitives types body

[Thaulino]

Details of change

Added the proper handling for primitves in request bodies
Related issue: closes #11984

Added primitives to src/tests of cpp-qt

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Technical committee

@muttleyxd
@etherealjoy
@wing328

[wing328]

Tested locally and the result is good:

PASS   : UserApiTests::initTestCase()
QDEBUG : UserApiTests::createUserTest() got a request body
PASS   : UserApiTests::createUserTest()
QDEBUG : UserApiTests::createUsersWithArrayInputTest() got a request body
PASS   : UserApiTests::createUsersWithArrayInputTest()
QDEBUG : UserApiTests::createUsersWithListInputTest() got a request body
PASS   : UserApiTests::createUsersWithListInputTest()
QDEBUG : UserApiTests::deleteUserTest() Error happened while issuing request :  "Error transferring http://petstore.swagger.io/v2/user/rambo - server replied: Not Found, "
PASS   : UserApiTests::deleteUserTest()
QDEBUG : UserApiTests::getUserByNameTest() "johndoe"
PASS   : UserApiTests::getUserByNameTest()
QDEBUG : UserApiTests::loginUserTest() "{\"code\":200,\"type\":\"unknown\",\"message\":\"logged in user session:1652608027710\"}"
PASS   : UserApiTests::loginUserTest()
PASS   : UserApiTests::logoutUserTest()
QDEBUG : UserApiTests::updateUserTest() got a request body
PASS   : UserApiTests::updateUserTest()
PASS   : UserApiTests::cleanupTestCase()
Totals: 10 passed, 0 failed, 0 skipped, 0 blacklisted, 84ms
********* Finished testing of UserApiTests *********
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  02:00 min
[INFO] Finished at: 2022-05-15T17:47:07+08:00
[INFO] ------------------------------------------------------------------------

[wing328]

@Thaulino thanks for the PR, which has been merged into the master.

[rejuce]

the issue still persist for bool type
const ::OpenAPI::OptionalParam &body

the same fix can be applied

QByteArray output = QByteArray::number(body.value());