Update iced_rs + related dependencies to 0.12.1

[yeastplume]

Keeping iced_rs up to date, but should also gain some new essential features such as the ability to display large editable text areas.

• Updating custom table and header widgets
• All styles updated with new structs
• Move widgets crate into core crate due to new trait implementation requirements
  [In Progress..]

[yeastplume]

• Moved table widgets into fork of iced_aw, with intention of submitting them upstream