tests: migrate to insta binary snapshots

[CommanderStorm]

This PR migrates us to insta's binary snapshots.
These snapshots were added via

• chore(deps): Bump insta from 1.40.0 to 1.41.1 #1563
• Binary snapshots (in-memory) mitsuhiko/insta#610

Currently, this PR is not mergable as the binary snapshots don't actually work. I encountered these two bugs:

• the binary snapshots get created as FILENAME.snap.new.png. This naming is inconsistent with how other snapshots are created.
• Re-running the tests creates different metadata files which contain different data:

  ---
  source: martin/src/sprites/mod.rs
  - assertion_line: 273
  expression: png
  - extension: png
  - snapshot_kind: binary
  ---
  +
  

  Yes, I looked if I am using the same versions of insta, I am. cargo test and cargo insta still provide really weird results

=> to be mergable, this PR would need work upstream.
I am going to try to write this up during the christmas holidays and provide a fix upstream.

[nyurik]

Note that image (binary) snapshots might not be ... stable, i.e. SDF->PNG, especially when multiple images are packed as a single sprite might produce slightly different results on different platforms. So in short - this might cause more confusion than its worth. Maybe. I am not saying lets not do it, i'm saying we may not get what we want in some cases - so we should check multiple platforms on this on

[CommanderStorm]

I don't quite see where platform issues might come into image encoding/optimisation.
They SHOULD encode the same way, right?

The conclusion does not change though.
This is blocked upstream first before we can even consider running it through our CI.

[nyurik]

well, technically any hashmap-based implementation is already randomized - so even that may produce different results for image packing. Plus any kind of SVG->PNG encoding might in theory differ depending on arm64 vs x64 (in theory)...