All no-format files should have a default type, and, therefore, a default size

[dsoprea]

Currently, files that were placed by Google Drive, for example, may not have a specific type. Rather, it will require you to specify a type in order to download it. Because of this, the traditional size of such a file will be (0) (see [https://github.com/dsoprea/GDriveFS#format-management]).

We need to 1) have a default mapping of file-extensions to types, and 2) fallback to electing the first available type. In so doing, we can adopt more traditional filesystem behavior, whereby remote files can be copied with no more effort than a traditional filesystem, and we can accurately enumerate, tally, and determine sizes using commands more similar to traditional filesystems.