feat(forc-fmt): enhance forc-fmt --path behaviour flexibility

[eightfilms]

In this PR I discovered that there was some bug introduced with a previous PR i made refactoring forc-fmt. We should enhance the flexibility of forc-fmt to allow different behavior based on the --path input:

1. If --path points to a sway file, it only formats that file.
2. If --path points to a directory, it walks the directory and formats all sway files within.
3. If --path points to a package manifest, it only formats the source of that package.
4. If --path points to a workspace manifest, if formats all the member packages.

Currently forc-fmt only works on point 2. A PR should be opened to address 3 and 4.

As for 1, Further conversations with @mitchmindtree has also led to some insights regarding the desired behaviour of forc-fmt, which was emulated after cargo fmt:

cargo fmt is meant to work on workspaces/manifests and rustfmt is more primitive in the sense that it accepts only a file/list of files to format. In our case, we do not distribute swayfmt + forc-fmt. A previous PR i made introduced single file formatting file forc fmt <PATH_TO_FILE>. This is to emulate rustfmt.

I was thinking if we should keep this behavior, but I think for consistency's sake, we should also include --path for single file formatting.