Angle parsing: allow NESW

To specify latitudes and longitudes, it would be really helpful if the angle parsing would accept specifying N/S, E/W directions. (e.g. as used by wikipedia)

At the moment, this raises an error:

In [1]: from astropy.coordinates import Angle                                             
In [2]: Angle('45°55′12″N')
    ValueError: Invalid character at col 9 in angle '45°55′12″N'                                                           

[maxnoe]

I started looking into this

[maxnoe]

@DShivansh Here is a brilliant talk by David Beazly you might find interesting: https://www.youtube.com/watch?v=zJ9z6Ge-vXs