Remove FileInfo.path

[ry]

Closes #1770

depends on denoland/std#398 in deno_std
depends on #2361

[ry]

I will need to remove this from deno_std first:

~/src/deno> ./target/debug/deno fmt badly_formatted.js
Compiling https://raw.githubusercontent.com/denoland/deno_std/master/prettier/main.ts
/Users/rld/Library/Caches/deno/deps/https/raw.githubusercontent.com/denoland/deno_std/master/prettier/main.ts:183:38 - error TS2339: Property 'path' does not exist on type 'FileInfo'.

183     const parser = selectParser(file.path);
                                         ~~~~
/Users/rld/Library/Caches/deno/deps/https/raw.githubusercontent.com/denoland/deno_std/master/prettier/main.ts:185:34 - error TS2339: Property 'path' does not exist on type 'FileInfo'.

185       checks.push(checkFile(file.path, parser, prettierOpts));
                                     ~~~~
/Users/rld/Library/Caches/deno/deps/https/raw.githubusercontent.com/denoland/deno_std/master/prettier/main.ts:211:38 - error TS2339: Property 'path' does not exist on type 'FileInfo'.

211     const parser = selectParser(file.path);
                                         ~~~~
/Users/rld/Library/Caches/deno/deps/https/raw.githubusercontent.com/denoland/deno_std/master/prettier/main.ts:213:36 - error TS2339: Property 'path' does not exist on type 'FileInfo'.

213       formats.push(formatFile(file.path, parser, prettierOpts));
                                       ~~~~

cc @kt3k