Replace InvalidArgumentError with ServerError

[Uzlopak]

InvalidArgumentError or invalid_argument is not a oauth2-error. It is used by oauth2-server to indicate errors like that specific internal implementation is wrong. E.g. Request is missing header. Also the HttpStatusCode of 500 clearly indicates that it is a ServerError and not something what the enduser can control.

https://datatracker.ietf.org/doc/html/rfc6749#section-4.1.2.1
https://datatracker.ietf.org/doc/html/rfc6749#section-4.2.2.1

[jankapunkt]

Please also add, which parts of the code are affected and which tests need to be updated.

[Uzlopak]

Its actually scattered all over the place. It is everywhere used where an InternalServerError should be thrown because the implementor made an implementation error.

[Uzlopak]

We could also just patch the InvalidArgumentError to extend ServerError or change invalid_argument to server_error.