[✨] Named slots based on element type and some more improvements

[DustinJSilk]

Is your feature request related to a problem?

(Sorry for adding multiple requests to a single ticket!)

I've been working with slots for a while now, and there's a few things that are difficult to achieve. These are a few improvements which would be great to add to the library, if possible:

• A named slot but based on the element type.
  Often elements used in named slots are different types, it would be great if we could define the slot as <Slot element="p" /> and then all p elements would project there. Prop called either element/type/el
• Add a class attribute to the <Slot /> component that gets added to the injected element
  This means that content added to a component can be given strict styles defined in the component it is used in
• Slots without an element. (Maybe its not even possible)
  The extra dom element can be tricky. Developers adding to a components children need to think if the element they use is compatible with where it is being projected. For example, you cant put a p inside a p. Its also an extra element that could be avoided

Describe the solution you'd like

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Describe alternatives you've considered

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Additional context

No response

[gioboa]

We moved this issue to qwik-evolution repo to create a RFC discussion for this.
Here is our Qwik RFC process thanks.