IDL4CPP — Specify bounds checking

Reporting this for bounded sequences, but very likely this has to be addressed for all bounded types. The spec says "NOTE—In any case, bound checking on bounded sequences may be performed at serialization time, raising an
exception or reporting an error if necessary", but this should be more strict to my idea, the bounds check must be performed, and the spec should specify which exception is raised when the bound is not respected

Specify that middleware implementations may mandate specific bound checking mechanisms

This issue tries to convey that middleware implementations may introduce more explicit bound checking mechanisms.