#964 - Check if polytope is bounded on construction

[schillic]

Closes #964.

[mforets]

Here i have an API / aesthetic concern: i see no need to add a new method validate_boundedness, since we already have isbounded. We do need a new name for the keyword argument, which following other conventions throughout could be called check_boundedness.

[schillic]

We need it because isbounded(::HPolytope) does not perform any checks.

[mforets]

Ok. What about the keyword in the constructor? I slightly prefer check_boundedness.

[schillic]

The last two commits are new. Can you check again?

[mforets]

lgtm