Expanding types / type safety in js

While adding the small adjustments to the priority queue in #189 I took a small stab at using jsdoc style comments and // @ts-check to get some type safety.

Overall summary of changes / example changeset can be viewed here: https://github.com/matterport/3DTilesRendererJS/pull/1

• Add a generic type to LRUCache / PriorityQueue which enables some type safety of dev time in the TilesRendererBase.js file.

• Add more detailed Tile types

  • TileBase: intended to be the baseline type of the object from the 3d-tiles spec
  • Tile: Intention here was that this would be the type exposed for the PriorityQueue, and these would be considered the 'documented' values as used by the priority functions which the end-user can replace.
  • TileInternal: Provide some documentation of what the internally used tile properties are for developers to work with, not intended for real publishing, but after turning on the // @ts-check in the TilesRendererBase, this ended up being the type needed for the typescript checking to function?!
    TilesRendererBase.js

Add jsdoc type import, and // @ts-check magic comment.. the import type comments are pretty cumbersome, but I feel like they'll help the maintaining experience over time? I thought there was a better way to reference existing .d.ts files, but I'm not finding it offhand yet?!

TilesRendererBase.js:

Start with TilesRendererBase.js and the existing LRUCache and PriorityQueue definitions. Review the example changeset linked in the issue, including its JSDoc imports, @ts-check usage, and TileBase, Tile, and TileInternal types. Done means the intended type safety and developer-facing type documentation are applied consistently without breaking the JavaScript code.