[unitaryhack] Request for new matplotlib drawing styles

[trentfridey]

Context:
Adds styles requested in #2555

Description of the Change:

Adds the solarized light and dark styles to the available styles for drawer

Benefits:
Adds more options for clean and readable circuit diagram graphics

Related GitHub Issues:
#2555

[codecov]

Codecov Report

Merging #2662 (75ac23b) into master (4b7b59b) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #2662   +/-   ##
=======================================
  Coverage   99.59%   99.59%           
=======================================
  Files         249      249           
  Lines       20256    20280   +24     
=======================================
+ Hits        20173    20197   +24     
  Misses         83       83           

Impacted Files	Coverage Δ
pennylane/drawer/style.py	100.00% <100.00%> (ø)

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[albi3ro]

@trentfridey Thanks for the excellent contribution!

It looks like you've got all the code figured out, which is always nice to see.

Initially, I was going to ask for more contrast between the background and text, but upon viewing them in my dark-themed IDE, they looked wonderful.

One minor change that made the graphics much clearer was:

plt.rcParams['patch.linewidth'] = 3.0

I had to set the 'patch.linewidth' in the black_white style as well.

I'd also like to see how qml_drawer.rst looks with a 3x2 table instead of 5x1. The images start to get a bit too small with 5x1.

[albi3ro]

Looks excellent!

Just need to run black -l 100 pennylane/drawer/style.py and I'm happy to approve +1

[albi3ro]

@trentfridey So close! but now it looks like black -l 100 needs to be run on a test now too. These minor things can be a bit of a nuisance, but they make things much easier in the long term.

[albi3ro]

Excellent!
Thanks for the great contribution 🎉