ENH: empty() method for EA/Series/Index

[jbrockmendel]

There are a few places where we need an empty array-like of the same type+dtype as self. e.g. in #23431 I used self._data[:0]. A dedicated empty() method might pretty that up.

#23431 (comment)

[gfyoung]

Reminds me a little of #549.

[nmusolino]

I have needed something just like this for DataFrames as well.

Note that Index, Series, and DataFrame already have a Boolean .empty attribute indicating whether the object is empty.

What about a function pandas.empty_like(), or pandas.empty(), or pandas.emptied() ? Note that “empty_like” is already used by numpy for something pretty different: the numpy.empty_like function returns an array of the same shape, with uninitialized data.