standardize internal naming conventions that distinguish the relevant game

[rsek]

i reckon the problem with using Ironsworn as the distinguishing label for "Classic" Ironsworn is that it's also the label used for all games collectively.

i'm thinking a standard that goes something like...

• Ironsworn* indicates that something that applies across both Ironsworn and Ironsworn: Starforged (when it's necessary to make a distinction from e.g. FoundryVTT's version of something): IronswornActor
• Classic* indicates that something is exclusive to the original Ironsworn, but not exclusive to Ironsworn: Delve: ClassicSettlement
• Delve* indicates that something is exclusive to Ironsworn: Delve : DelveSiteDenizen
• Starforged* indicates that something is exclusive to Ironsworn: Starforged: StarforgedSettlement
• SunderedIsles* when it shows up

Originally posted by @rsek in https://github.com/ben/foundry-ironsworn/pull/422#discussion_r940743437