[7.4.z] datasources-web-server base layers description does not specify which subsystems are available

Upon some discussions taken on EAPSUP-369, we have realized that the description of datasources-web-server on trimming capabilities doesn't specify which subsystems are included by default in this base layer. The other base layers that enhance this describe the Jakarta Specifications and the subsystems added on top of this one.

It looks like its customers and GSS team can benefit from this description to understand better which subsystems are included on each Galleon layer.

I open this Jira as a possible enhancement on this documentation that maybe the Doc team can see it useful as well, if not, please feel free to close it.