Lots of reused code

[the-emerald]

Although the reactionscroll.py has a couple of overriden methods that have to be custom-defined by any module wishing to use it, the code behind on_reaction_add and on_reaction_remove, as well as a few helper functions as seen in demo.py are simply copy-pasted.

Is it possible to rework it so that a Scroller object is created inside a module, and then creates listeners? It can also contains helper functions or whatever. As I see it, right now the scroller is only tasked with creating and storing a chain of embeds, but not responsible for listening for scrolling commands.

[the-emerald]

This goes in hand nicely with your NOAA module @hxtk, I notice that in the (pre-work) version if a second user calls another station while the first user is still scrolling, because the scroller updates to the new station, the scrollable actually changes to the second station.

If we could somehow separate the Scroller and something like a EmbedChain it would be great.