Function parse_porcelain 

pub fn parse_porcelain(output: &str) -> Result<ChangeSet>

Parse git status --porcelain=v1 -z output

Format: XY filename\0 where:

• X = index status
• Y = working tree status
• filename = path relative to repo root

Special cases:

• Renames: R old\0new\0
• Copies: C old\0new\0
• Untracked: ?? filename\0
• Ignored: !! filename\0
• Merge conflicts: UU filename\0, AA filename\0, etc.

See: https://git-scm.com/docs/git-status#_short_format

Errors

Returns GitError::InvalidOutput when the porcelain stream is malformed (missing status codes, filenames, or rename/copy metadata).