Channel Info Mixins classloading issue in case no Channel Info class configured

This relates to HSTTWO-4704 and HSTTWO-4321

In org.hippoecm.hst.platform.configuration.channel.ChannelUtils#getChannelInfo there is code at the end that can fail :

T parametersInfo = (T) factory.createInvokerProxy(proxyClasses[0].getClassLoader(), invoker, proxyClasses);

The proxyClasses are a combination of the Channel Info class and the Channel Info Mixins, see HSTTWO-4321. However, if there is no hst:channelinfoclass specified, the Channel Info class will be

org.hippoecm.hst.configuration.channel.ChannelInfo

and proxyClasses[0] will refer to this class. This class however is an interface from the hst-api which is part of the shared lib and has the shared classloader as classloader.

Since the mixin classes (proxyClasses[1.....x]) are classes part of the end project, they have the website webapp classloader! As a result,

T parametersInfo = (T) factory.createInvokerProxy(proxyClasses[0].getClassLoader(), invoker, proxyClasses);

will fail because the shared class loader doesn't see the mixin classes.

Instead of proxyClasses[0].getClassLoader(), always the website classloader should be used since that one can also see the shared classes