Add CRAFT Model

[Bennett-Petzold]

Converting from https://github.com/clovaai/CRAFT-pytorch. The original code is MIT-licensed.

TODO:

• Verify Python -> Rust translation is correct (mainly the interpolate step)
• Figure out how to set interpolate bi-linear interpolation in Candle
• Allow for post-processing model (Option in construction)?
  • Requires output from the middle of the model, so can't be kept in a separate model
• Allow for training (currently locked behind Sequence not supporting forwardT, could break apart Sequence into operations instead)
• Preprocessing
• Postprocessing
• Verification against original Python approach
• Example usage