- adds an API key authentication provider

[baywet]

related microsoft/kiota#1902

[rkodev]

@baywet thinking this functionality might be better residing in https://github.com/microsoft/kiota-http-go

[andrueastman]

Hey @rkodev,
I believe due to the fact that this works by manipulating the RequestInformation abstaction and not http language specific types, it should be okay to keep it here.
If we move this to the HTTP library, this would imply someone using a potential alternative/custom/user-defined http library for Kiota would still need to also pull the http library or re-implement the API key Authentication provider when it actually not really tied to a specific transport mechanism.