feat: New icon app in contrib including icon picker for wide set of icon libraries

[fsbraun]

This PR adds djangocms_frontend.contrib.icon as an optional replacement for djangocms_icon.

It inherits djangocms-frontend's tabbed user interface and adds manipulation for icon size and color.

Currently, it contains a copy of Gilles Migliori's universal icon picker with some adaptation to its css to better work with django-cms.

In contrast to djangocms-icons icon picker it also supports Font Awesome 6.

Other supported (and partly even bundled) icon sets:

• Bootstrap icons
• Elegant icons
• Feather icons
• Fomatic UI icons
• Font awesome (regular, solid and brands)
• Foundation icons
• Happy icons
• Icomoon
• Material icons (filled, outlined, sharp, two-tone)
• Open iconic
• Tabler icons
• Weather icons
• Steve Schoger's Zondicons

This would be the core of release 1.1 of djangocms-frontend.

[codecov[bot]]

Codecov Report

Merging #110 (2a212a0) into master (fcbf65f) will increase coverage by 0.11%. The diff coverage is 86.79%.

@@            Coverage Diff             @@
##           master     #110      +/-   ##
==========================================
+ Coverage   86.30%   86.42%   +0.11%     
==========================================
  Files         110      118       +8     
  Lines        2980     3086     +106     
  Branches      323      334      +11     
==========================================
+ Hits         2572     2667      +95     
- Misses        310      312       +2     
- Partials       98      107       +9     

Impacted Files	Coverage Δ
...ntend/contrib/accordion/migrations/0001_initial.py	100.00% <ø> (ø)
..._frontend/contrib/alert/migrations/0001_initial.py	100.00% <ø> (ø)
..._frontend/contrib/badge/migrations/0001_initial.py	100.00% <ø> (ø)
...s_frontend/contrib/card/migrations/0001_initial.py	100.00% <ø> (ø)
djangocms_frontend/contrib/carousel/cms_plugins.py	100.00% <ø> (ø)
djangocms_frontend/contrib/carousel/forms.py	100.00% <ø> (ø)
...ontend/contrib/carousel/migrations/0001_initial.py	100.00% <ø> (ø)
...ontend/contrib/collapse/migrations/0001_initial.py	100.00% <ø> (ø)
...rontend/contrib/content/migrations/0001_initial.py	100.00% <ø> (ø)
...s_frontend/contrib/grid/migrations/0001_initial.py	100.00% <ø> (ø)
... and 27 more

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.