FindCURL: Fix hardcoded outdated protocols and features

This removes the hardcoded known protocols and features and only checks
whether the specified component(s) by the
`find_package(COMPONENT|OPTIONAL_COMPONENT <components>...)` call are
found and listed by either the pkg-config or the curl-config tool. When
curl is found via its CMake package configuration file, this issue
wasn't relevant.

Additionally, this also removes two internal FindCURL module variables
`CURL_KNOWN_PROTOCOLS` and `CURL_KNOWN_FEATURES`.

Redundant fatal error thrown is also removed as this is handled by the
`find_package_handle_standard_args()`.

Fixes #26866