Separate the bean-validation subsystem from the 'cdi' Galleon layer

When we created the 'cdi' layer we included bean-validation in it to avoid the need to create a separate layer. But we're starting to have basically a layer (or more) per subsystem, plus there are a number of layers that depend on 'cdi' and don't have a logical reason to bring along b-v for their use case (e.g. WFLY-12755). So I think we should break out b-v.

Here are the current layers that depend on 'cdi':

$ git grep "layer name=\"cdi\""
galleon-pack/src/main/resources/layers/standalone/cloud-profile/layer-spec.xml:        <layer name="cdi" optional="true"/>
galleon-pack/src/main/resources/layers/standalone/ee-security/layer-spec.xml:        <layer name="cdi"/>
galleon-pack/src/main/resources/layers/standalone/observability/layer-spec.xml:        <layer name="cdi"/>
galleon-pack/src/main/resources/layers/standalone/open-tracing/layer-spec.xml:        <layer name="cdi"/>
testsuite/test-feature-pack/src/main/resources/layers/standalone/jaxrs-server/layer-spec.xml:        <layer name="cdi" optional="true"/>

For 'cloud-profile' and 'jaxrs-server' I would add b-v as a new optional dependency. I think most users who might be wanting b-v would be using one of those two, or, in the images, the 'cloud-server' descendent of 'cloud-profile', so they'll still get b-v.

People directly depending on 'cdi' or expecting to get it via 'observability' or 'open-tracing' will need to adapt their config.