Migrate Schwarz icon library to GitHub

[larsrickert]

Migrate our Schwarz icon library to GitHub / OpenSource so we can use it for onyx.

Acceptance criteria

• icon library is provided as SVGs
• icon color can be set
• icon size can be set to a set of predefined sizes defined by @jannick-ux
• every icons should be hidden from aria (because they are not meaningful standalone)
• icons are showcases in the docs and can be either downloaded as SVG or copied to clipboard as code
• icon library is published as npm package @sit-onyx/icons

[JoCa96]

• icon library is provided as SVGs

  • We definitely should offer the optimized SVG assets
  • but I am still convinced that icon paths are the way to go, or is that out-of-scope here?

• every icons should be accessible so that e.g. screen readers recognise it e.g. as "trash icon"

  • i am unsure about this, it might be better to force the user to define the alt text:
  • a lot of the icons have ambiguous meaning and use-cases
  • we have hundreds of icons, so this will require a lot of work to write useful alt texts.
  • Probably best to discuss this with ux

• We need to consider and onboard the stackit colleagues which also consume the stackit icons

• SVGs should be optimized

[larsrickert]

Follow up ticket #285