Fix #2104: fmt incorrectly using 1-indexing for columns

[jkelleyrtp]

• Fix: [[email protected]] dx fmt breaks file #2104

Two issues in autofmt:

• Incorrectly using 1-indexing for columns when we should be doing 0-indexing
• Comments were being written for attributes even when those comments did not belong to those attributes. We now double check who owns the whitespace before writing it out

While doing this overhaul, I also finally ditched the prettier-please crate for the original prettyplease crate, meaning we have 1 fewer vendored crates to maintain (bringing that down the total down to 0!). This does lead to slightly less performance (since we can't make a File out of a borrowed Expr, but should be imperceptible in practice.