Convert mesh-extras to TypeScript

[Zyie]

Description of change

Pre-Merge Checklist

Simple enough conversion.

Fixes a few types in Mesh and made data optional in Buffer.update

• Lint process passed (npm run lint)
• Tests passed (npm run test)

[codecov-io]

Codecov Report

Merging #6396 into dev will increase coverage by 1.49%.
The diff coverage is 71.42%.

@@            Coverage Diff             @@
##              dev    #6396      +/-   ##
==========================================
+ Coverage   78.37%   79.86%   +1.49%     
==========================================
  Files          64       61       -3     
  Lines        3759     3502     -257     
==========================================
- Hits         2946     2797     -149     
+ Misses        813      705     -108

Impacted Files	Coverage Δ
...s/canvas/canvas-sprite/src/CanvasSpriteRenderer.js	65.51% <100%> (ø)	⬆️
packages/canvas/canvas-renderer/src/BaseTexture.js	100% <100%> (ø)	⬆️
packages/canvas/canvas-mesh/src/NineSlicePlane.js	89.36% <50%> (-1.75%)	⬇️
...nvas/canvas-graphics/src/CanvasGraphicsRenderer.js	35.51% <70%> (+1.81%)	⬆️

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[ivanpopelyshev]

It is weird without default params, we had ones in v4

https://github.com/pixijs/pixi.js/blob/v4.x/src/mesh/Mesh.js#L40

However, I can justify vertices? that because PlaneGeometry uses that constructor. Its fine to set up actual data later. This version is OK, good job!