Toaster: make closeAll function async to allow awaiting it

[mayank99]

Changes

Instead of hoping that promises resolve correctly, users can now await close calls to our toaster before opening other toasts.

(async () => {
  await toaster.closeAll();
  toaster.informational();
})();

Does it fix #1005? Does it break anything? Lets find out!!

Edit: It does break things. I'll figure out a different approach. Stay tuned.

Edit 2: Fixed failing tests by not awaiting creation functions. See #1025 (comment).

Testing

Pending.

Docs

Pending

[mayank99]

i wanted to make all methods awaitable, but that would cause breaking changes for users who are using the return value like this:

const { close } = toaster.positive();

i thought about keeping backwards compatibility by adding a promise as a new property in the return value.

Suggested change

	// cannot `await` this, for backwards compat with the return value
	this.updateView();
	return { close: () => this.closeToast(currentId) };
	const close = () => this.closeToast(currentId);
	const updatePromise = this.updateView();
	const done = new Promise<boolean>(async (resolve) => {
	await updatePromise;
	resolve(true);
	});
	return { close, done };

but no one has asked for it and i don't see the benefit yet, so i decided against it.