Add profile for Epson TM-U325D

[dilworks]

Just got a old Epson TM-U325D (with serial interface board UB-S01, connected via an RS232 to USB cable, although there is also the option to upgrade to native USB via the UB-U03II interface board), and learned about this project via python-escpos. Been tinkering with this for a while (it's my first time messing with a proper receipt printer!), and found there is amazingly so little documentation for this ~20 year old printer, even from Epson itself! (and they did sold it for quite some time, it was just not as popular as, say, the TM-U200 series).

Here are some info I've found so far:

• The only documentation about supported ESC/POS commands for this printer only seem to exist on versions 10.03/10.04 of the old Epson APG from circa 2006 (older versions do not list it, newer versions removed it for the TM-U220D). Amazingly, there is a completely unrelated printer that emulates the U325D: the Ithaca POSjet 1500, which also comes with a nice ESC/POS command reference including a few undocumented (albeit irrelevant for those actually printing things) commands!
• This is a impact printer (standard 76mm paper rolls, can use 1 or 2-ply paper) with a slip printing slot. I've tested the slip printer with python-escpos under Linux and it works as expected.
• The only supported image printing mode is via bitImageColumn (ESC *), and only with high density mode disabled (otherwise the printer prints garbage text!)
• No native barcode support whatsoever.
• No automatic cutter - the cut command just feeds the paper to the cut position as expected.
• The Ithaca POSjet 1500 manual mentions a color printing command (ESC r) on its U325D ESC/POS emulation mode, but none of the U325-applicable Epson manuals mention it (and the user manual doesn't even make any reference to the ERC-38BR 2-color ribbon, the only color option for those printers), so I suspect it may be not supported, but then I don't have one of those 2-color ribbons for testing...
• FWIW, it works with CUPS using Epson's own GPL'd raster printer driver for impact printers.

Functionality-wise, this looks like a smaller TM-U200D (for which we also don't have a profile here) with a slip slot.
Would be glad to contribute with testing to prepare a compatible profile for this printer - thermals are nice, but impact dot matrix is basically forever :)

[dilworks]

After doing some more research, and comparing profiles, looks like the existing profile for the TM-U220D is a good starting profile for the TM-U325D, as it's pretty much a perfect feature match (except maybe for the 2-color printing).

This printer also seems to have a resolution of "400 half-dot units per line" as per the specs on the user manual, so most likely 200 dots per line (and matches the experiences at python-escpos/python-escpos#598 , down to the same profile errors!)

[dilworks]

I don't really do this "git" stuff so I won't be filing a PR, but here is my first shot at a profile for the TM-U325D:
TM-U325D.yml

Tested with python-escpos - sample printouts.

• This printer supports double (high) density printing for bitmaps, but only horizontally.
• Centering works wonderfully once figuring out the right dimensions for everything - this IS a 200 point per line printer.
• Printer defaults to Font B (40cpl) at startup/reset.
• Sometimes bitmap printing ends a bit misaligned, or with stray characters printed at one side, dunno why
• Dunno if this is a python-escpos or a printer firmware bug, but sometimes it loses its mind when trying to print out things on alternate codepages, and anything over ASCII 127 ends as question signs.
• Codepages 0 to 5 are supported, plus 254 and 255 which are... empty spaces.