test: rework ephemeralkeyinfo to run in parallel

Remove:
- use of tls global so tests can run in parallel
- test counting in favour of common.mustCall()
- limit of only one cipher suite per ephemeral key type tested

The last change  will allow adding TLS 1.3 cipher suites and testing
'ECDH' key info with them.

PR-URL: https://github.com/nodejs/node/pull/25409


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>