parse: add feature to parse and upload msg files

[joe-prosser]

Adds a feature to parse unicode msg files and upload them directly to a source. Extracts the minimum information we require from the msg using cfb crate

[tommilligan]

Nice work getting this up and running, it looks excellent to me. Honestly I don't think there's anything stopping us from just backporting this code into the api, so we can support msg files on the server side there (if we actually want to do that).

Nothing from me - just style/nits which I've pushed review commits for

[tommilligan]

You don't need .clone() here - .replace(...) returns a Cow which when you call to_string(), will only call clone() internally if necessary.

docs

Suggested change

	clean_headers_string = CONTENT_TYPE_MIME_HEADER_RX
	.clone()
	.replace(&headers_string, "")
	.to_string();
	clean_headers_string = CONTENT_TRANSFER_ENCODING_MIME_HEADER_RX
	.clone()
	.replace(&clean_headers_string, "")
	.to_string();
	clean_headers_string = CONTENT_TYPE_MIME_HEADER_RX
	.replace(&headers_string, "")
	.to_string();
	clean_headers_string = CONTENT_TRANSFER_ENCODING_MIME_HEADER_RX
	.replace(&clean_headers_string, "")
	.to_string();

[tommilligan]

Written slightly strangely - nested if normally indicates you can use a combinator, in this case .ok(). Also you negate the if statement for some reason, which makes it harder to read?

Suggested change

	.filter_map(|path| {
	if let Ok(path) = path {
	if !path.path().extension().is_some_and(|msg| msg == "msg") {
	None
	} else {
	Some(path)
	}
	} else {
	None
	}
	})
	.filter_map(|path| {
	let path = path.ok()?;
	if path.path().extension().is_some_and(|msg| msg == "msg") {
	Some(path)
	} else {
	None
	}
	})

[tommilligan]

As you call this more than once (again after the loop), you can easily pull this out into a closure:

    let send = |documents: &mut Vec<Document>| -> Result<()> {
        upload_batch_of_documents(
            client,
            &source,
            documents,
            transform_tag,
            *no_charge,
            &statistics,
        )?;
        documents.clear();
        Ok(())
    };

[tommilligan]

nit: don't have to clone here

Suggested change

	attachment_name_path.push(STREAM_PATH_ATTACHMENT_FILENAME.clone());
	attachment_name_path.push(&*STREAM_PATH_ATTACHMENT_FILENAME);

* dereferences your Lazy instance to the inner value, then & borrows the PathBuf into a Path (which is all you need for push here)

[tommilligan]

Here and in a few other places you don't actually need a PathBuf, just a Path, which allows you to remove a bunch of clone()s elsewhere.