Indie Auth Identifier Validator

see spec https://indieauth.spec.indieweb.org/#user-profile-url

User Profile URL

Users are identified by a [URL]. Profile URLs MUST have either an https or http scheme, MUST contain a path component (/ is a valid path), MUST NOT contain single-dot or double-dot path segments, MAY contain a query string component, MUST NOT contain a fragment component, MUST NOT contain a username or password component, and MUST NOT contain a port. Additionally, hostnames MUST be domain names and MUST NOT be ipv4 or ipv6 addresses.

Some examples of valid profile URLs are:

https://example.com/
https://example.com/username
https://example.com/users?id=100

Some examples of invalid profile URLs are:

example.com - missing scheme
mailto:user@example.com - invalid scheme
https://example.com/foo/../bar - contains a double-dot path segment
https://example.com/#me - contains a fragment
https://user:pass@example.com/ - contains a username and password
https://example.com:8443/ - contains a port
https://172.28.92.51/ - host is an IP address