tls: TLSSocket emits 'error' on handshake failure

Removes branch that would make TLSSocket emit '_tlsError' event if
error occured on handshake and control was not released, as it was
never happening.  Added test for tls.Server to ensure it still emits
'tlsClientError' as expected.

Note that 'tlsClientError' does not exist in the v4.x branch so this
back-port emits 'clientError' instead.  See also pull request #4557.

Fixes: https://github.com/nodejs/node/issues/8803
PR-URL: https://github.com/nodejs/node/pull/8805
Refs: https://github.com/nodejs/node/pull/4557


Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Fedor Indutny <fedor@indutny.com>