OAuth2 Auth provider incorrectly validating Access Tokens

### Questions

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### Version

Version: 4.3.8

### Context

Whilst trying to set up an OIDC client with discovery against a keycloak instance, I discovered that the access token which is in JWT form was not being decoded and added to the session as I expected it would be. The non decoded format is present on the session.

### Steps to reproduce

1. Run a keycloak instance somewhere and create a realm and client and a user
2. Set up the vertex OIDC client with discovery
3. Have an endpoint that prints out the session
4. Run the program and log in and inspect the session

### Extra

The reason the decoded form is not stored is because of https://github.com/eclipse-vertx/vertx-auth/blob/f0215a105380d47ecdefa260e2ebe0aa321a5297/vertx-auth-oauth2/src/main/java/io/vertx/ext/auth/oauth2/impl/OAuth2AuthProviderImpl.java#L542
Which calls `validToken` Which internally does https://github.com/eclipse-vertx/vertx-auth/blob/f0215a105380d47ecdefa260e2ebe0aa321a5297/vertx-auth-oauth2/src/main/java/io/vertx/ext/auth/oauth2/impl/OAuth2AuthProviderImpl.java#L643

With the comment
```
// https://openid.net/specs/openid-connect-core-1_0.html# $3.1.3.7.
// The Client MUST validate that the aud (audience) Claim contains its client_id value registered at the Issuer
// identified by the iss (issuer) Claim as an audience. The aud (audience) Claim MAY contain an array with more
// than one element. The ID Token MUST be rejected if the ID Token does not list the Client as a valid audience,
// or if it contains additional audiences not trusted by the Client.
```

This fails for the keycloak access token as the `aud` is not the client ID it is `account`

`https://openid.net/specs/openid-connect-core-1_0.html# $3.1.3.7` refers to the section for `ID Token Validation`. In this case the token is not an ID token so should not be subject to the same validation logic. The validation logic for access tokens is stated in section `3.2.2.9`

Therefore there are a couple of options / parts:
1. switch https://github.com/eclipse-vertx/vertx-auth/blob/f0215a105380d47ecdefa260e2ebe0aa321a5297/vertx-auth-oauth2/src/main/java/io/vertx/ext/auth/oauth2/impl/OAuth2AuthProviderImpl.java#L643 to `idToken && jwtOptions.getAudience() == null` instead of `||` so that this validation is skipped for access tokens, fixing this bug
2. Add in the rules from `3.2.2.9` for access tokens (possibly a new feature or extension)