Refactor & update for Stardew Valley 1.3

[Pathoschild]

Update all mods for Stardew Valley 1.3 and refactor where needed to minimise dependencies and improve crossplatform support. This is a tracking ticket.

To do

• General:
  • [x] Minor refactoring (remove unused code, migrate to new NuGet package reference format, use SMAPI's Harmony DLL, etc).
  • [x] Standardise update checks.
  • [x] Review and fix unofficial updates.
  • [x] Finish updating mods for Stardew Valley 1.3.
  • [x] Fix crossplatform compatibility issues.
• Advanced Location Loader:
  • [x] Fix error when a content pack specifies format versions like 1.2.9 instead of 1.2 (e.g. Stardew Valley Expansion).
• Entoarox Framework:
  • [x] Fix compatibility with other mods which change player speed.
• More Animals:
  • [x] Move assets into conventional assets subfolder.
  • [x] Unpack XNB assets into normal PNG files.

[Pathoschild]

Partially updated to Stardew Valley 1.3 by @Slamerz via #46, #47, #48, #50, #51, #52.

Per discussion with @Entoarox:

• remove dependencies on Entoarox Framework where unneeded;
• remove custom update check logic (just using standard SMAPI update keys).