SpringBoot Support custom token validators for OAuth2 Resource Server auto-configuration

Added injections of OAuth2TokenValidator<Jwt> beans to ReactiveOAuth2ResourceServerJwkConfigurationand OAuth2ResourceServerJwtConfiguration to provide an easy way to add custom validations and still use auto-configuration (#35783)

Closes gh-35783

Comment From: romangr

Rebased to the main branch since some tests unrelated to the PR failed in the previous run https://github.com/spring-projects/spring-boot/actions/runs/5258769234/jobs/9667349868?pr=35874

Comment From: wilkinsona

Thanks for the PR, @romangr. I've left a few comments for your consideration when you have a minute.

Comment From: wilkinsona

@romangr, thanks very much for making your first contribution to Spring Boot.