52. implement Split<S, D>

Just like String.prototype.split(), please implement Split<S, D>.

type A = Split<'BFE.dev', '.'> // ['BFE', 'dev']
type B = Split<'bfe.dev', 'e'> // ['bf', '.d', 'v']
type C = Split<'bfe.bfe.bfe', 'bfe'> // ['', '.', '.', '']