Remove the org.wildfly.management.expression-resolver-extension-registry

The WFCORE-5490 work replaces resolver extension integration via the Capability API with integration via the ExtensionContext. But, because capability API approach was included in WF 26, I left it there, but deprecated. This JIRA is to remove it.

Likely I will do this in the next feature release after the one that follows 26. This capability was brand new in 26 and is not documented in the capability registry, so I see no need to keep it around long. On the contrary we should get rid of it quickly before someone stumbles on it and uses it despite the deprecation. (I think that's unlikely, but still...)