Move existing flavortext to flavortext module

[JohnathonNow]

There are many pieces of dialog throughout the code that should be moved to the flavortext module. In addition to keeping things organized, it also makes potential translation easier if anyone eventually ever cares about that.

[adinalini]

Can you elaborate with an example, I am a little confused, would love to take this up

[JohnathonNow]

Right now we have user displayed strings throughout the entire codebase, such as
here. I think it would be better for that line to be changed to

add_action(FT_HAG_SUMMON_SNEK);

and then a line added to flavortext.h that says:

#DEFINE FT_HAG_SUMMON_SNEK ("The old hag summons a dangerous snek!")

with this done to all displayed strings.
Formatted strings are a little more tricky, though.