Improve static typing and formatting

[elliotfontaine]

Hi !
While experimenting with a "resource database" view built on top of DynamicTable, I made a first pass on static typing and code formatting.

• Static typing improvements (still ~150 warnings remaining):
  elliotfontaine/yard-godot@45e2aae
• Formatting cleanup using the VSCode GDScript formatter:
  elliotfontaine/yard-godot@8dbd662

The typing changes still need more testing to ensure they don’t introduce runtime issues.
This issue is mainly informational for now; I can open a PR if these changes align with the project’s direction.