Refactor telescope_names and telescope_sizes into a separate module

[drewoldag]

There are several places in the code base where "telescope_name" is defined as a default input parameter like ['4m', '8m'] as well as "telescope_sizes" as [4, 8].

We should probably refactor that code, and pull those definition into a distinct module like "telescopes". And we should create it in such a way that it follows the open/closed principal.

At first though, it could be a simple dictionary in a telescopes.py module.

telescopes = {
    "4m": 4,
    "8m": 8
}