Unified models for progress tracks and clocks

[rsek]

Changes of note (WIP)

• data models for progress and truth JEPs
• JEP subtype-specific methods moved to their respective models
• ProgressLike data model; abstract class to provide constants and functions common to progress track-like objects (with the exception of classic bonds, which might get rewritten as part of Explore representing classic-style bonds as ActiveEffects #818 , anyways)
• LegacyTrack (extends ProgressLike); each player character legacy track is now a single object whose source data is {ticks: number, xpSpent: number}
• ProgressTrack (extends ProgressLike), which replaces every progress track that isn't a legacy track or bond track
  • standardizes several common progress operations and computations
  • marked ticks standardized to ticks
  • subtype changes:
    • subtype bond renamed to connection; uses SF's "Forge a Bond" move when rolling progress
    • new subtype delve, which is only used internally; it identifies delve progress tracks to progress-related methods; uses delve's "Locate Your Objective" move when rolling progress
  • most documents that use a progress track embed it in system.track
    • the exception is progress JEP, which are intentionally more "atomic".
• everything clock-shaped now uses the Clock data model
• ChallengeRankField renamed to ChallengeRank; supplies most challenge rank constants and utility functions as statics