poll: <For> with custom equality/keying

[LiQuidProQuo]

<For> component only supports referential equality.
do we want more?

key_by

// provide a transformer to generate a unique key
<For  each={[ {id:1 value:0}, {id:3 value}  ]} 
         key_by{(o)=>o.id}
>
</For>

equals

// provide the equality function 
<For equals={(a,b)=>boolan}>
</For>

composable key_by and equals

<For  each={[ {id:1 value:0},  {id:3 value}  ]} 
         key_by={(o)=>o.id} 
         equals={ (a,b)=>  a === b  }  // a and b are transformed by key_by callback
  >
</For>

3rd party primitive

solidjs-community/<Key>

<Key each={items()} by={item => item.id} fallback={<div>No items</div>}>
  {item => <div>{item()}</div>}
</Key>

[lxsmnsyc]

I think this is just a repeat of #813 which motivated the creation of solid-primitives/keyed