feat: As a user, I want to be able to configure additional authorization params in the OIDC plugin, so that I can be compliant with my identity provider

[TrevorSmith-msr]

Description

As a user, I want to be able to configure additional authorization params in the OIDC plugin, so that I can be compliant with my identity provider.

Simply put, Auth0 requires an additional audience parameter in the request parameters of the /authorize request. Currently, I can't configure this additional parameter, preventing me from using Auth0 as an identity provider for OIDC.

Luckily, the lua-resty-openidc library already supports this: https://github.com/zmartzone/lua-resty-openidc/blob/734a3f4dba0faf037abe993c678e43b1bab3025a/lib/resty/openidc.lua#L348

I have actually already added this and will submit a PR shortly.