Add various inclusion functors

[ScriptRaccoon]

This PR adds the following inclusion functors and decides all of their properties:

1. Haus → Top
2. CRing → Ring
3. TorsAb → Ab
4. FinGrp → Grp
5. FinAb → Ab
6. ∅ → Set

New indistinguishable functors

• Before this PR, the indiscrete topology functor Set → Top was already indistinguishable from the forgetful functor Ab → Grp (based on the properties in the database, of course). Now, however, the forgetful functor CRing → Ring is also indistinguishable from both.
• The new functor TorsAb → Ab is indistinguishable from the discrete topology functor Set → Top.
• The new functor ∅ → Set is indistinguishable from the span endpoints inclusion functor 2 → Span.

And these are just the new indistinguishable pairs. The page /missing lists even more. This indicates that more functor properties need to be added to the database.