The helper `get_localized_time` should also accept string

[ale-rt]

See:

plone.api/src/plone/api/portal.py

Lines 200 to 204 in a7f69d5

	def get_localized_time(
	datetime: Optional[Union[date, DateTime, datetime]] = None,
	long_format: bool = False,
	time_only: bool = False,
	) -> str:

and:
https://github.com/plone/plone.base/blob/18f2f4c7ca24da0d6b26bf9c25a061c7cf3ec037/src/plone/base/i18nl10n.py#L221-L224

Originally posted by @ale-rt in #592 (comment)