feat: multiple actions support and api improvements

[anwarulislam]

This PR adds support for multiple actions.

Example:

 toast.message('Event has been created', {
  action: [
    {
      label: 'Cancel',
      onClick: (e, toast) => toast.deleteToast(200)
    },
    {
      label: 'Confirm',
      onClick: () => console.log('Confirm')
    }
  ],
  duration: 10000000
})

Added new callback parameter in onClick function which through we can now pass the deleteToast function. And call it if it's needed. The function accepts delay as parameter to delete the toast.

[jamesgeorge007]

Looking good, left a few comments. Also, we could rename the deleteToast method as part of the toast instance received in the onClick callback to dismiss to be consistent with the existing API.

[jamesgeorge007]

LGTM, left a few minor comments, not blockers per se, can be revisited separately.

[jamesgeorge007]

It'll be good to obtain a reference to the timeout ID returned by the inner setTimeout call and clear it during the unmount phase.

[jamesgeorge007]

We need not return the timeoutID since it's available in the global scope and consumed in the unmount life cycle hook.

[jamesgeorge007]

Referring to the toast instance from the onClick callback here can prevent closing other toasts.