v0.5.0

Added

• Index searching to data manager.
• Search highlighting in data manager.
• "Unlabel" option to remove previously labeled data from training set.

Fixed

• Data column sorting not working.
• Needing to render the notebook's first model view cell twice for ipyvuetify
  stylesheets to propagate. (Use icat.initialize() now, instead of
  pn.extension())