Make http_client Response body property generic - part of #369

[mattTea]

Make Response body property generic within http_client package. This is part of the TODO Hunting issue #369

---

For the Pull Request to be accepted please check:

• The PR has a meaningful title.
• If the PR refers to an issue, it should be referenced with the GitHub format (#ID).
• The PR is done to the develop branch (new features) or the master branch (releases).
• The code pass all PR checks.
• All public members are documented using KDoc.
• The code follow the coding conventions stated at the contributing.md file.

[jaguililla]

I was offline since Friday... I'll review this PR along this week, sorry for the delay, and thank you for the contribution!

[mattTea]

No probs at all! 🙂

[jaguililla]

Nice job... Thanks!!! :)