Allow naming of CSP groups

[MattWindsor91]

Something that might tidy up the use of CSP groups in conformance testing is the ability to name the group, with the result that everything in the group gets shunted into a module of the same name, and all of the definitions get a QualifiedName qualifier. For instance, the difference between

untimed csp {
    process Foo_P
}

and

untimed csp Foo {
    process P
}

[MattWindsor91]

CSP groups have been pared back since this issue was filed, so I'm closing this.