fix: Add maxBuffer to expensive git commands

[sammcj]

Hopefully a fix for #253

Default is 1x1024x1024, this seems to be a common increase especially if a project contains unicode characters.

• https://www.hacksparrow.com/nodejs/difference-between-spawn-and-exec-of-node-js-child-rocess.html
• https://nodejs.org/docs/latest-v16.x/api/child_process.html#maxbuffer-and-unicode
• https://stackoverflow.com/questions/61540352/rangeerror-err-child-process-stdio-maxbufferstdout-maxbuffer-length-exceeded

[sammcj]

replaced with #281