SearchableList.async, async filter function

[julien-levarlet]

Hi,
I made the changes from #162, the filter function is now async.
I also added a debouncer to make sure the filter function isn't called too often (can be tuned using asyncDebounceTime).

It's working, but I think it would be better if the asyncListFilter is canceled before calling it again, instead of calling it multiple times.

[koukibadr]

@julien-levarlet I did a full review to your PR but now I cannot rebase it there's conflict with main branch can you resolve it please

[julien-levarlet]

@koukibadr, thank you,
I don't know why it doesn't work, it tells me that I am up-to-date with main.
If you prefer I can rebase my branch on main and push it in a new branch or force push in this branch. Is that better for you ?

[koukibadr]

@julien-levarlet yes the best way is the push it as a new branch rebased with main to make sure there's no conflicts
you can send me a new PR and we merge it directly