Add a warning when the length of delays are longer than the supplied data

[seabbs]

Some users may accidentally supply PMFs that are longer than the observed data (or intentionally in some rare settings). In theory this should be handled internally by slicing them to match the maximum length but in practice (i.e. #735) this may lead to issues. Even if this is working as intended we likely want to warn the users that this is happening vs doing it automatically.

We likely want to make this warning once per session so as not to annoy advanced users who want this functionality.

[seabbs]

This is resolved right?

[jamesmbaazam]

Not that I'm aware of. I fixed the other one though (#738).

[sbfnk]

Do we really want this? I can see that this was a problem in the case of #735 but that's been resolved. In the more general case I would think what the user believes about a certain delay (and what its max should be) is independent of the data.

[seabbs]

I just don't really like things happening automatically under the hood that users may not be aware of. It also seems to have led to a lot of issues for users (nearly all recent issues we have had I think)