Support parsing MacOS XXXXX.partial.emlx emails attachments

[lfcnassif]

Those *.partial.emlx files have their attachments extracted and put into a separate folder by some Apple Mail app. IPED detects the email has attachments and extracts/links to them (in the viewer), but, when clicking on the linked/extracted attachments, they don't open because they are invalid/corrupted, their contents were subtracted from the original email. We should open/link to the extracted attachment present into another file system folder.

[lfcnassif]

@FelipeFcosta, since you did something similar in #1286, would you like to take a look at this? This is much simpler, since the attachments can be easily found from the email file name and we already have a parser for the standard eml/emlx format.

[FelipeFcosta]

@FelipeFcosta, since you did something similar in #1286, would you like to take a look at this? This is much simpler, since the attachments can be easily found from the email file name and we already have a parser for the standard eml/emlx format.

Yes, I'll look into it