Unauthenticated paths support for Shiro provider

Looks like we have only support unauthenticated paths for

• JWTProvider
• HadoopAuthProvider
• SSOCookieProvider

Shiro auth provider does not have support for unauthenticated path parameter.

see KNOX-2582 and KNOX-2393

This can be enabled by adding the following param to Shiro authentication provider

           <param>
                <name>urls./knoxtoken/api/v1/jwks.json</name>
                <value>anon</value>
            </param>