refactor: use struct types for claim related types (#283)

* oidc: add regression tests for token claim json

this helps to verify that the same JSON is produced,
after these types are refactored.

* refactor: use struct types for claim related types

BREAKING CHANGE:
The following types are changed from interface to struct type:

- AccessTokenClaims
- IDTokenClaims
- IntrospectionResponse
- UserInfo and related types.

The following methods of OPStorage now take a pointer to a struct type,
instead of an interface:

- SetUserinfoFromScopes
- SetUserinfoFromToken
- SetIntrospectionFromToken

The following functions are now generic, so that type-safe extension
of Claims is now possible:

- op.VerifyIDTokenHint
- op.VerifyAccessToken
- rp.VerifyTokens
- rp.VerifyIDToken

- Changed UserInfoAddress to pointer in UserInfo and
IntrospectionResponse.
This was needed to make omitempty work correctly.
- Copy or merge maps in IntrospectionResponse and SetUserInfo

* op: add example for VerifyAccessToken

* fix: rp: wrong assignment in WithIssuedAtMaxAge

WithIssuedAtMaxAge assigned its value to v.maxAge, which was wrong.
This change fixes that by assiging the duration to v.maxAgeIAT.

* rp: add VerifyTokens example

* oidc: add standard references to:

- IDTokenClaims
- IntrospectionResponse
- UserInfo

* only count coverage for `./pkg/...`

example/client/api/api.go

@@ -76,7 +76,7 @@ func main() {
 		params := mux.Vars(r)
 		requestedClaim := params["claim"]
 		requestedValue := params["value"]
-		value, ok := resp.GetClaim(requestedClaim).(string)
+		value, ok := resp.Claims[requestedClaim].(string)
 		if !ok || value == "" || value != requestedValue {
 			http.Error(w, "claim does not match", http.StatusForbidden)
 			return

example/client/app/app.go

@@ -60,7 +60,7 @@ func main() {
 	http.Handle("/login", rp.AuthURLHandler(state, provider))
 
 	// for demonstration purposes the returned userinfo response is written as JSON object onto response
-	marshalUserinfo := func(w http.ResponseWriter, r *http.Request, tokens *oidc.Tokens, state string, rp rp.RelyingParty, info oidc.UserInfo) {
+	marshalUserinfo := func(w http.ResponseWriter, r *http.Request, tokens *oidc.Tokens[*oidc.IDTokenClaims], state string, rp rp.RelyingParty, info *oidc.UserInfo) {
 		data, err := json.Marshal(info)
 		if err != nil {
 			http.Error(w, err.Error(), http.StatusInternalServerError)

example/client/github/github.go

@@ -13,6 +13,7 @@ import (
 	"github.com/zitadel/oidc/v2/pkg/client/rp"
 	"github.com/zitadel/oidc/v2/pkg/client/rp/cli"
 	"github.com/zitadel/oidc/v2/pkg/http"
+	"github.com/zitadel/oidc/v2/pkg/oidc"
 )
 
 var (
@@ -43,7 +44,7 @@ func main() {
 	state := func() string {
 		return uuid.New().String()
 	}
-	token := cli.CodeFlow(ctx, relyingParty, callbackPath, port, state)
+	token := cli.CodeFlow[*oidc.IDTokenClaims](ctx, relyingParty, callbackPath, port, state)
 
 	client := github.NewClient(relyingParty.OAuthConfig().Client(ctx, token.Token))