Demo of pilot's new look, first try

[JunliXiao]

Ref #510

I got a new look for pilot gui using the Python library qt-material, as below:

Compared to my macOS dark mode native look:

As you can see, the qt-material default (light-red) themes looks cool, but its font and buttons etc, not so much
And it lacks a simple white-ish, light mode theme, without light COLORS

Now my primary goal is to let users select light mode or dark mode
Either one of them is platform dependent (Windows/Mac), but you can choose freely
Then I can extend to provide more fancy-looking themes...

Next step I'm going to dive into Qt code and see how to customize

[c1ydehhx]

Wrong indent.

Suggested change

	-Dpybind11_DIR=`pybind11-config --cmakedir` \
	-DCMAKE_TOOLCHAIN_FILE=${DEVENVPREFIX}/lib/cmake/Qt6/qt.toolchain.cmake \
	-Dpybind11_DIR=`pybind11-config --cmakedir` \
	-DCMAKE_TOOLCHAIN_FILE=${DEVENVPREFIX}/lib/cmake/Qt6/qt.toolchain.cmake \

[c1ydehhx]

This change is not related by this PR. Please revert it.

[yungyuc]

The PR is work in progress and I will change it to be so.

Fix #xxx

Do not add issue operating commands in PR like above. I'll edit your comment to remove it.

I got a new look for pilot gui using the Python library qt-material

This is a good start. Mac does not use material design. Perhaps we need to find a configuration for the mac light theme. Could you please help look into it?

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Additional points to address:

• Formatting and history issues.

[JunliXiao]

Perhaps we need to find a configuration for the mac light theme. Could you please help look into it?

Yes, I'm looking into it now.

Since I want the light mode to look like the same as platform native, or very close to, I try to locate the default style sheets(qss). Interestingly, Qt does not set the default look from stylesheets, but it at runtime directly creates and applies the platform-specific subclass of QStyle. (QStyle works at level lower than qss) For Windows and Linux there exist subclass files; for macOS thing are tricky: it goes to find some .dylib at some path and load it for use, which I still can't find that on my mac🤔

Other than that, I will try using qss, to be able to style custom colors.