[os] readlink should support getting the target's printname in Windows

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2020-05-30.16:31:07.665>
labels = ['3.8', '3.9', '3.10', 'type-feature', 'library', 'OS-windows']
title = "os.readlink should support getting the target's printname in Windows"
updated_at = <Date 2020-06-15.18:19:06.289>
user = 'https://github.com/eryksun'

bugs.python.org fields:

activity = <Date 2020-06-15.18:19:06.289>
actor = 'mattblovell'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)', 'Windows']
creation = <Date 2020-05-30.16:31:07.665>
creator = 'eryksun'
dependencies = []
files = []
hgrepos = []
issue_num = 40827
keywords = []
message_count = 1.0
messages = ['370389']
nosy_count = 6.0
nosy_names = ['paul.moore', 'tim.golden', 'zach.ware', 'eryksun', 'steve.dower', 'mattblovell']
pr_nums = []
priority = 'normal'
resolution = None
stage = 'needs patch'
status = 'open'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue40827'
versions = ['Python 3.8', 'Python 3.9', 'Python 3.10']