Alert: make alert dismissable

[derrok]

Closes #397

This PR adds the ability to make alerts dismissable.

[derrok]

This commit adds the default position for the toast. Now, you don't need to write
$this->success('All done!', 'toast-bottom toast-end')
each time in each of your components if you want to change the default position of your toast. You can write
<x-toast position="toast-bottom toast-end" />
in your layout and use the toast with the simple $this->success('All done!') command.

[robsontenorio]

Thanks ! Looks good.

On the next opportunity , please send one PR per feature. Because it’s easier to rollback in case of problems.

But I will handle this as is.