feat: Token Revocation, Request Object and OP Certification (#130)

FEATURES (and FIXES):
- support OAuth 2.0 Token Revocation [RFC 7009](https://datatracker.ietf.org/doc/html/rfc7009)
- handle request object using `request` parameter [OIDC Core 1.0 Request Object](https://openid.net/specs/openid-connect-core-1_0.html#RequestObject)
- handle response mode
- added some information to the discovery endpoint:
  - revocation_endpoint (added with token revocation) 
  - revocation_endpoint_auth_methods_supported (added with token revocation)
  - revocation_endpoint_auth_signing_alg_values_supported (added with token revocation)
  - token_endpoint_auth_signing_alg_values_supported (was missing)
  - introspection_endpoint_auth_signing_alg_values_supported (was missing)
  - request_object_signing_alg_values_supported (added with request object)
  - request_parameter_supported (added with request object)
 - fixed `removeUserinfoScopes ` now returns the scopes without "userinfo" scopes (profile, email, phone, addedd) [source diff](https://github.com/caos/oidc/pull/130/files#diff-fad50c8c0f065d4dbc49d6c6a38f09c992c8f5d651a479ba00e31b500543559eL170-R171)
- improved error handling (pkg/oidc/error.go) and fixed some wrong OAuth errors (e.g. `invalid_grant` instead of `invalid_request`)
- improved MarshalJSON and added MarshalJSONWithStatus
- removed deprecated PEM decryption from `BytesToPrivateKey`  [source diff](https://github.com/caos/oidc/pull/130/files#diff-fe246e428e399ccff599627c71764de51387b60b4df84c67de3febd0954e859bL11-L19)
- NewAccessTokenVerifier now uses correct (internal) `accessTokenVerifier` [source diff](https://github.com/caos/oidc/pull/130/files#diff-3a01c7500ead8f35448456ef231c7c22f8d291710936cac91de5edeef52ffc72L52-R52)

BREAKING CHANGE:
- move functions from `utils` package into separate packages
- added various methods to the (OP) `Configuration` interface [source diff](https://github.com/caos/oidc/pull/130/files#diff-2538e0dfc772fdc37f057aecd6fcc2943f516c24e8be794cce0e368a26d20a82R19-R32)
- added revocationEndpoint to `WithCustomEndpoints ` [source diff](https://github.com/caos/oidc/pull/130/files#diff-19ae13a743eb7cebbb96492798b1bec556673eb6236b1387e38d722900bae1c3L355-R391)
- remove unnecessary context parameter from JWTProfileExchange [source diff](https://github.com/caos/oidc/pull/130/files#diff-4ed8f6affa4a9631fa8a034b3d5752fbb6a819107141aae00029014e950f7b4cL14)

pkg/utils/crypto.go

@@ -1,68 +0,0 @@
-package utils
-
-import (
-	"crypto/aes"
-	"crypto/cipher"
-	"crypto/rand"
-	"encoding/base64"
-	"errors"
-	"io"
-)
-
-func EncryptAES(data string, key string) (string, error) {
-	encrypted, err := EncryptBytesAES([]byte(data), key)
-	if err != nil {
-		return "", err
-	}
-
-	return base64.RawURLEncoding.EncodeToString(encrypted), nil
-}
-
-func EncryptBytesAES(plainText []byte, key string) ([]byte, error) {
-	block, err := aes.NewCipher([]byte(key))
-	if err != nil {
-		return nil, err
-	}
-
-	cipherText := make([]byte, aes.BlockSize+len(plainText))
-	iv := cipherText[:aes.BlockSize]
-	if _, err = io.ReadFull(rand.Reader, iv); err != nil {
-		return nil, err
-	}
-
-	stream := cipher.NewCFBEncrypter(block, iv)
-	stream.XORKeyStream(cipherText[aes.BlockSize:], plainText)
-
-	return cipherText, nil
-}
-
-func DecryptAES(data string, key string) (string, error) {
-	text, err := base64.RawURLEncoding.DecodeString(data)
-	if err != nil {
-		return "", err
-	}
-	decrypted, err := DecryptBytesAES(text, key)
-	if err != nil {
-		return "", err
-	}
-	return string(decrypted), nil
-}
-
-func DecryptBytesAES(cipherText []byte, key string) ([]byte, error) {
-	block, err := aes.NewCipher([]byte(key))
-	if err != nil {
-		return nil, err
-	}
-
-	if len(cipherText) < aes.BlockSize {
-		err = errors.New("Ciphertext block size is too short!")
-		return nil, err
-	}
-	iv := cipherText[:aes.BlockSize]
-	cipherText = cipherText[aes.BlockSize:]
-
-	stream := cipher.NewCFBDecrypter(block, iv)
-	stream.XORKeyStream(cipherText, cipherText)
-
-	return cipherText, err
-}