Devices: Initial Add of Waveshare 1602 Support

[gsexton]

In particular, you should look at how I'm handling the backlight and let me know if it presents issues.

[codecov]

Codecov Report

Attention: Patch coverage is 75.82090% with 81 lines in your changes missing coverage. Please review.

Project coverage is 52.3%. Comparing base (f007d15) to head (98d1d05).
Report is 6 commits behind head on main.

Files with missing lines	Patch %	Lines
aip31068/dev.go	83.3%	25 Missing and 11 partials ⚠️
pca9633/dev.go	73.3%	16 Missing and 11 partials ⚠️
waveshare1602/1602.go	0.0%	18 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##            main    #100     +/-   ##
=======================================
+ Coverage   51.8%   52.3%   +0.5%     
=======================================
  Files        102     109      +7     
  Lines      13073   13847    +774     
=======================================
+ Hits        6772    7247    +475     
- Misses      6009    6279    +270     
- Partials     292     321     +29     

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[maruel]

looks good, thanks!