Implements a potential structure for splitting the SFX event mapping
into smaller individual files for maintainability.
- Remove inventory events for now: For a later commit.
- No longer panic when there is a failure parsing the sfx file: log the error and not play sfx.
This is an event based approach to SFX sounds. There is a specific
character sound event mapper which determines sfx to play based on
character or NPC state, as well as emitting sfx events for
non-character-triggers such as levelling up.
