I read through every file and applied a couple of rustfmt suggestions. The brace placement and alignment of items on similar lines has been made consistent, even if neither are rustfmt's default style (a file has been put in place to enforce this). Other changes are:
• Alphabetical imports and modules
• Comma placement at the end of match blocks
• Use newlines and indentation judiciously
• Spaces around associated types
• Spaces after negations (it makes it more clear imho)
• Comment formatting
• Use early-returns and Optional `?` where appropriate