Fix drawstyle plot_histogram

[ericpre]

Progress of the PR

• Fix hs.plot_plot_histograms drawstyle - see https://matplotlib.org/stable/api/prev_api_changes/api_changes_3.3.0.html#passing-line2d-s-drawstyle-together-with-linestyle-is-removed
• update docstring,
• [N/A] update user guide
• add an changelog entry in the upcoming_changes folder (see upcoming_changes/README.rst),
• Check formatting changelog entry in the readthedocs doc build of this PR (link in github checks)
• add tests,
• ready for review.

Minimal example of the bug fix or the new feature

import hyperspy.api as hs
import numpy as np

img = hs.signals.Signal2D(np.random.chisquare(1,[10,10,100]))
img2 = hs.signals.Signal2D(np.random.chisquare(2,[10,10,100]))
ax = hs.plot.plot_histograms([img, img2], legend=['hist1', 'hist2'])

[codecov]

Codecov Report

Merging #2810 (4bdeb85) into RELEASE_next_patch (69e8a23) will increase coverage by 0.05%.
The diff coverage is 92.30%.

@@                  Coverage Diff                   @@
##           RELEASE_next_patch    #2810      +/-   ##
======================================================
+ Coverage               77.37%   77.42%   +0.05%     
======================================================
  Files                     202      202              
  Lines                   30108    30108              
  Branches                 6579     6578       -1     
======================================================
+ Hits                    23295    23312      +17     
+ Misses                   5066     5051      -15     
+ Partials                 1747     1745       -2     

Impacted Files	Coverage Δ
hyperspy/drawing/utils.py	73.11% <92.30%> (+2.80%)	⬆️
hyperspy/misc/eels/eelsdb.py	60.86% <0.00%> (-4.35%)	⬇️
hyperspy/axes.py	86.34% <0.00%> (ø)
hyperspy/_signals/lazy.py	90.67% <0.00%> (ø)
hyperspy/signal.py	76.24% <0.00%> (+0.03%)	⬆️
hyperspy/io.py	84.18% <0.00%> (+0.79%)	⬆️

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[jlaehne]

A few more corrections to the docstring, otherwise LGTM.