Add support for Relative Approots non intrusive

[cptrodolfox]

By using an alternative with oauth2RedirectUri users of the library can set up their own redirect URIs.

As part of Stack Builders Inc. Hacktoberfest 2023 event.

[pbrisbin]

This almost feels too easy!

Let me make sure I understand...

Previously,

Providers would create an OAuth2 with oauth2RedirectUri set to Nothing, and this function would then build a callback using PluginR and set it to that. This relies on getParentUrlRender which relies on approot being non-relative.

Now,

Providers may set an oauth2RedirectUri ahead of time and it will be respected.

This allows an app that uses a relative approot to function, as long as they use providers that are handling oauth2RedirectUri themselves, and ensuring it's absolute through whatever provider-specific variables they may accept.

This seems kind of niche to me, but it's very non-intrusive and totally opt-in, so sounds great!

[cptrodolfox]

@pbrisbin I have done some code changes to avoid calling the getParentUrlRender if the oauth2RedirectUri is set.

[pbrisbin]

LGTM. I will merge/release once I see it's Green.

[cptrodolfox]

LGTM. I will merge/release once I see it's Green.

Thanks for the feedback.

[pbrisbin]

Released as v0.7.1.3.

[DavidMazarro]

@cptrodolfox Thanks for the contribution! Remember to add the following line in the PR's description so that the contribution can be considered valid for Stack Builders' Hacktoberfest 2023 event:

As part of Stack Builders Inc. Hacktoberfest 2023 event.