Qt5: Added missing datatype handlers for QByteArray for swagger-type "byte"

[philicious]

Now you can have sth like this in your swagger and it will work with Qt5 SDK

  ProductObject:
    type: object
    properties:
      image:
        type: string
        format: byte

the property will be base64 encoded/decoded to/from JSON

[wing328]

@philicious thanks for the PR to improve the Qt5 C++ generator.

I noticed that you described the image as type: string, format: byte (base64-encoded string). Should it be better described as type: string, format:binary instead?

Ref: https://github.com/OAI/OpenAPI-Specification/blob/master/versions/2.0.md#data-types

[philicious]

@wing328 actually no. Binary would be an octet stream. And I think you cannot wrap any octet / byte in JSON as that's a string. So you need encoding

[wing328]

@philicious thanks for the swift response and PR merged.

[wing328]

@philicious for your upcoming PRs, please also run ./bin/qt5-petstore.sh to update the Qt5 C++ Petstore sample.

[philicious]

oh right @wing328 , will do. I forgot about it since my last PR 😇

btw I think its only #3410 missing now for fully implementing swagger spec datatypes in Qt5 generator.