Get file status for a single file.
This is not quite the same as calling git_status_foreach_ext()
with
the pathspec set to the specified path.
Output combination of git_status_t values for file
The file to retrieve status for relative to the repo workdir
0 on success, GIT_ENOTFOUND if the file is not found in the HEAD, index, and work tree, GIT_EAMBIGUOUS if path
matches multiple files or if it refers to a folder, and -1 on other errors.