Support Seeed Studio's "Grove Nixie Displays"

[mungewell]

While exploring #28 I came across a couple of displays from Seeed Studio, which look like they could be supported.

2-digit: https://www.seeedstudio.com/Grove-0-54-Red-Dual-Alphanumeric-Display-p-4031.html 4-digit: https://www.seeedstudio.com/Grove-0-54-Red-Quad-Alphanumeric-Display-p-4032.html

The 2-digit one looks like (from LED module datasheet) it's similar the 'HT16K33Segment14', each digit is on a single COM and uses 15 rows for all the segments.

The 4-digit one is a bit different. There is a COM for each digit, but it only uses 12 rows and the 'K', 'L' and 'Colon' segments are split off to a 5th COM. This would require some adjustments to the driver.

Note: I don't have either of these displays and I didn't find a supplier for Canada-land...