Improve error checking to Matrix parameters

[mutesplash]

De-duplicates code and also allows set_pixels to accept (str,int) as pixel specifications

Allow set_pixels() to defer display updates like set_pixel() does

Also, remove the exception in Device.off() for the Matrix by overriding it

[mutesplash]

Updated!

[mutesplash]

I guess I better get flake8 installed if I want this merged.

[chrisruk]

Hey, sorry about that, I've just been working on linting the code, you'll need -

flake8
flake8-pylint

Then you can do: 'PYTHONPATH=. flake8 .' from the main part of the repo.

[chrisruk]

This now fails to run the example in docs for me.

With:

python3.9 docs/buildhat/matrix.py 
Traceback (most recent call last):
  File "/home/pi/Repositories/python-build-hat/docs/buildhat/matrix.py", line 8, in <module>
    matrix.clear(("red", 10))
  File "/home/pi/Repositories/python-build-hat/buildhat/matrix.py", line 121, in clear
    color = Matrix.normalize_pixel(pixel)  # pylint: disable=too-many-function-args
TypeError: normalize_pixel() takes 1 positional argument but 2 were given

Also at the moment I'm not really using the type annotation feature.

I think staticmethod should be used rather than classmethod.

[mutesplash]

Ugh, these tuples...

I put the type annotations in to make the linter be quiet. If you'd rather use the # directives, I'll change it back. I'll also use the staticmethod.

[mutesplash]

Ooookay, turned out those didn't help the linter anyway! It should work now?