Normalizes an origin for stable comparison: trims whitespace, lowercases, and strips trailing
slashes. It does not parse the value or rewrite ports, so https://a.com:443 stays as written.
Parameters
origin: string
an origin as written in a header or an allowlist entry
Normalizes an origin for stable comparison: trims whitespace, lowercases, and strips trailing slashes. It does not parse the value or rewrite ports, so
https://a.com:443stays as written.