Local file URL validation

[DUB1401]

Fails to validate URL for local file:

from validators import url

url("file:///var/www") # ValidationError(func=url, args={'value': 'file:///var/www'})

Excpected True, because this URL type standartizated in RFC 8089.

Error in _validate_netloc() function. It expected domain like var.com, but see directory var.

ValidationError(
	func=hostname,
	args={'value': 'var', 'skip_ipv6_addr': True, 'skip_ipv4_addr': False, 'may_have_port': True, 'maybe_simple': False, 'consider_tld': False, 'private': None, 'rfc_1034': False, 'rfc_2782': False}
)

May be we should skip netloc validation in some cases like file and add file scheme in _validate_scheme() function.

Works this code, but is it correct behaviour for common URL scheme?

from validators import url

url("file:///var/www", simple_host = True, validate_scheme = lambda x: x == "file") # True