Adding ICO and pathlib support for image

[hoxbro]

Added a ICO class to pane.image and pathlib conversion to pane.image and favicon in templates.

[philippjfr]

Not sure it's worth it to make a reference gallery item for ICO but we need to exclude it from the unit test that checks such an example exists.

[codecov]

Codecov Report

Merging #2757 (2e6f3d1) into master (80a66c3) will increase coverage by 0.63%.
The diff coverage is 88.88%.

@@            Coverage Diff             @@
##           master    #2757      +/-   ##
==========================================
+ Coverage   82.03%   82.67%   +0.63%     
==========================================
  Files         187      188       +1     
  Lines       23963    24070     +107     
==========================================
+ Hits        19658    19899     +241     
+ Misses       4305     4171     -134     

Impacted Files	Coverage Δ
panel/template/base.py	78.71% <40.00%> (-0.08%)	⬇️
panel/pane/__init__.py	100.00% <100.00%> (ø)
panel/pane/image.py	80.72% <100.00%> (+2.39%)	⬆️
panel/tests/pane/test_image.py	100.00% <100.00%> (ø)
panel/tests/test_docs.py	100.00% <100.00%> (ø)
panel/tests/command/test_serve.py	85.00% <0.00%> (ø)
panel/tests/conftest.py	95.90% <0.00%> (+0.21%)	⬆️
panel/pane/holoviews.py	79.65% <0.00%> (+0.21%)	⬆️
panel/pane/vtk/vtk.py	96.83% <0.00%> (+0.45%)	⬆️
panel/pane/plot.py	59.69% <0.00%> (+0.51%)	⬆️
... and 12 more

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[hoxbro]

I don't either see the need for a reference gallery item.

Should I also make the logo in BasicTemplate accept pathlib?

[philippjfr]

Should I also make the logo in BasicTemplate accept pathlib?

Yes, but maybe in a separate PR.

[MarcSkovMadsen]

Without a reference example, how would users know its supported? And what potential arguments are available?

[hoxbro]

I'm not opposed to adding a reference gallery of ICO.

Though, I don't think anybody will ever use an ICO pane directly but will rather pass a path or URL of an .ico file into a theme which will then just work. E.g., like what you did with awesome-panel.