Hot reloading assets

[Bombfuse]

Hot reloading assets during development is a big quality of life improvement, we should add a feature hotreload that tracks asset files.

Sprites - Track texture files, reload them in the rendering engine on change.
Aseprites - Track both animation files and sprite files, reload them in the rendering engine on change.
Sounds - Track sound files, track sound progress, reload them at the point they were playing at on change.

[Bombfuse]

We should be able to just use std::fs::Metadata to see if the modified date has changed compared to the date when the asset was stored, then read in the new data and replace the data in the asset store.

[Bombfuse]

Texture hotreloading complete

[Bombfuse]

Remaining work

• Fonts
• Sounds
• Any File (User marks a file for hot reloading by using loader().add_hotreload_target("some_file") which will add the file to the hotreload list)

[Bombfuse]

splitting out into multiple issues for better tracking

#112
#113
#114