Disk Device Manager: checks the raw content_name when editing a partition

also only provide a default name for partition containing a file system
fix #17958

Change-Id: Ib5a8928dc5272a400a99aa05b792201f3a6a2c7d
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5705
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

disk_systems: set filesystem name from partition name if exists.

* With GPT, partition entries store the name of the partition, so
use the stored name to initialise the name for the file system
when formatting.

Add FAT addon for DriveSetup

Tested with a 5MB image, seems to work.

There seems to be an issue with too long names though, or possibly names with spaces.

Also, technically it supports FAT12,16 and 32, so it should probably be renamed
in the interface.

Didn't check how to declare support for more than 1 partition types either.