tracking: improve the API to make foyer more user-friendly

[MrCroxx]

• Remove unnecessary generic type.
• Better cache builder for in-memory cache. feat: introduce CacheBuilder for in-memory cache #350
• Better cache builder for disk cache. feat: introduce store builder for disk cache for simplification #369
• Refine and unify the Key Value abstraction of im-memory cache and disk cache. feat: use serde to ser/de storage key and value #366
• Unify in-memory cache and disk cache build. feat: unify foyer in-memory cache and disk cache #391