Add option to generate "all information of HTTP request" in controllers

[atollk]

(This was actually described in #162 already but only authentication was implemented in #186)

Both Spring and Micronaut offer to inject an object into their controller methods which provides "all" data of a request. For example, query parameters can be accessed via a map. This can offer more flexibility to controller implementations.

For Micronaut, a new parameter is added to endpoint methods:

@Get
fun example(
  httpRequest: HttpRequest<T>,
) {/* ... */}

"T" in this example, refers to the body type, i.e. the "DTO" that could also be injected by using the @Body annotation.
For endpoints that accept no body, e.g. usual "GET" requests, we use * instead, i.e. HttpRequest<*>.

For Spring, this is almost the same, just that we use HttpEntity rather than HttpRequest.

This would cause a breaking change compared to current code generation (and might be undesirable to some developers anyway) so it'd need to be enabled conditionally with a flag.