UnoCSS support (3.0)

[evnchn]

Motivation

Due to various reasons it may not be good to have ourselves tied down to using Tailwind CDN JS

• Large size
• Performance reasons
• Lack of configurability

So this PR want to enable UnoCSS support, an atomic and configurable CSS engine.

Implementation

Compared to predecessor #4832, this is more clean because:

• Dark mode works without sketchy hacks
• Code is cleaned up in some places (shorter name allClasses, which generateStylesFromClasses takes no argument, cleaner for loop, etc)
• No need preset-wind <-> preset-wind3 hack, because of https://github.com/unocss/unocss/releases/tag/v66.5.3 by yours truly
• Now that we have CSS layering, stuff becomes more organized and simple.

Going over the changes briefly:

• Extract core libraries
• Expose option in ui.run ui.run_with and AppConfig
• Use UnoCSS in HTML and JS
• Ignore for precommit codespell

Progress

• I chose a meaningful title that completes the sentence: "If applied, this PR will..."
• The implementation is complete.
• Pytests have been added (b0fb62a).
• Documentation has been added (20e3916).

[evnchn]

57a3b33 tested and works.

// Modified from examples/custom_vue_element/counter.js to use Tailwind classes
export default {
  template: `
    <button
      @click="handle_click"
      :class="[
        'px-4 py-2 rounded-md transition-colors',
        value > 0 ? 'bg-green-200 hover:bg-green-300' : 'bg-gray-200 hover:bg-gray-300'
      ]"
    >
      <strong>{{ title }}: {{ value }}</strong>
    </button>
  `,
  props: {
    title: String,
  },
  data() {
    return {
      value: 0,
    };
  },
  methods: {
    handle_click() {
      this.value += 1;
      this.$emit("change", this.value);
    },
    reset() {
      this.value = 0;
    },
  },
};

[evnchn]

Spotted some mistakes while on the train

[evnchn]

Accidentally left this in there. Oh well. Let's remove this before we merge (or not, since it works)

[evnchn]

Actually is the observer needed? All of NiceGUI components do not add Tailwind classes programmatically...

Perhaps configurable? observer can be one of 3 values:

• None: No observer, most performant
• 'components': Catches components which add Tailwind classes programmatically
• 'full': Observes the entire body and misses nothing