Provide common capability for Remoting connectors

The EJB3 subsystem has an element <remote/> which performs a few different functions relating to external clients accessing EJBs on the server:

• sets up a Remoting connector service so that external clients may connect to the server using EJB / Remoting or EJB / HTTP Upgrade / Remoting
• sets up client mappings entries for those remote clients which are used in topology updates to allow the client to find the server's connectors

The Remoting subsystem has two connector types which may be supplied to the <remote connector-ref/> attribute. <connector name="remoting-connector"/> represents a Remoting endpoint and <http-connector name="http-connector"/> represents an Undertow listener which may be used with HTTP Upgrade.

At present, in the Remoting subsystem, these connectors have two separately defined capabilities:
// for <connector/>
private static final String CONNECTOR_CAPABILITY_NAME ="org.wildfly.remoting.connector";
static final RuntimeCapability<Void> CONNECTOR_CAPABILITY = RuntimeCapability.Builder.of(CONNECTOR_CAPABILITY_NAME, true).build();

// for <http-connector/>
private static final String HTTP_CONNECTOR_CAPABILITY_NAME = "org.wildfly.remoting.http-connector";
static final RuntimeCapability<Void> HTTP_CONNECTOR_CAPABILITY = RuntimeCapability.Builder.of(HTTP_CONNECTOR_CAPABILITY_NAME, true).build();

The proposal here is to allow referencing both connectors using a single capability base name, "org.wildfly.remoting.connector" to simplify specification of the capabilities which the <remote/> element needs (i.e. it may depend on one or the other). These are both dynamically named capabilities, so their names will vary based on the name of the management resource instance they represent. Because capability names are considered public API, the existing capability name for org.wildfly.remoting.http-connector cannot be removed to further simplify.