SerialConnect: Add localization.

Add localization for menus, statusbar and system name.

Change-Id: I85ef95c1ff940c6d794f49a859ff1b696b866839
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2602
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

XModem: fix start of CRC transfer

We can send the first block immediately when we receive the "C" for the
first time.

SerialConnect: handle cancelled file transfers.

The remote can cancel a file transfer by sending a CAN character.
Handle this by stopping the transfer and hiding the progress bar.

SerialConnect: implement XMODEM-CRC

This is a common extension to XMODEM, which replaces the checksum with a
more resilient CRC.
The receiver must explicitly enable this, so if the receiver doesn't
handle it, the traditional checksum is still used. Hence, this is
backwards-compatible with XMODEM.

SerialConnect: implement XMODEM send.