Use bitmapAdapter for costume upload

[fsih]

Resolves

Work toward scratchfoundation/scratch-svg-renderer#36
Depends on scratchfoundation/scratch-svg-renderer#43
Depends on scratchfoundation/scratch-vm#1315

Also fixes some places where we use info instead of info/2 for the rotation center. Info[0] appears to be costume width and info[1] appears to be costume height.

Proposed Changes

Attach bitmapAdapter
Use bitmapAdapter for file upload. The api is slightly different from the old importBitmap

Browser Coverage

Check the OS/browser combinations tested (At least 2)

Mac

• Chrome
• Firefox
• Safari

Windows

• Chrome
• Firefox
• Edge

Chromebook

• Chrome

iPad

• Safari

Android Tablet

• Chrome

[fsih]

The branch is up! This branch includes the new loading logic as well as all the bitmap assets, so you can actually load them.
After:
https://llk.github.io/scratch-gui/bitmapLibraryWithBitmapLoad/index.html

For comparison, here is the branch that just adds the bitmap assets.
Before:
https://llk.github.io/scratch-gui/bitmap/

Things to test:

• Anna, Calvert, Cassy, Dan, Football, Lamp are sprites / costumes with bitmap resolution 1, so they are double the size with the new loader
• Test that uploads of all file types and sizes and from camera get resized the same way in Before and After, and don't become blurry (jimp replacement was successful)

Question marks:

• Jodi and Sam have file type gif so they don't load in the paint editor on either version currently
• What does info[] mean?
  • In Before, when uploading individual costumes (not sprites), the rotation center is set to the bottom right corner instead of the center. info[0] is height and info[1] is width, not rotation center (try adding AZ pop down). This has been corrected in After
  • I think for other costumes, info[0] does indeed mean rotationCenterX and info[1] is rotationCenterY, because now in After, some costumes are not centered correctly (e.g. unicorn)

/cc @thisandagain

[kchadha]

As discussed offline, the rotation center should be updated to divide the info values by 2 for bitmap costumes (and all backdrops?) and leave the values as is for vector costumes.

[fsih]

Made a new issue for the orientation issue:
scratchfoundation/scratch-paint#554

[kchadha]

LGTM pending the package.json updates needed to make the build pass.