doc: rework tls for accuracy and clarity

Document all TLSSocket options:

- All the secure context options are valid options
  to a secureContext
- isServer modifies the default value of requestCert

Describe all tls.connect() variants:

- tls.connect(path) was undocumented
- tls.connect(port) was underdocumented, and its relationship to
  tls.connect(options) was obscure

Socket passed to tls.connect is user managed:

- Replace https://github.com/nodejs/node/pull/8996

Add documentation to:

- describe and add tests for the pfx and key variants, and describe how
  and when passphrase is used.
- describe tls cert and ca options
- describe buffer forms of tls crl option
- describe tls cipher option and defaults
- fix link to Crypto Constants
- describe that honorCipherOrder sets SSL_OP_CIPHER_SERVER_PREFERENCE.
- describe tls ecdhCurve/dhparam options
- describe tls secureProtocol option
- describe tls secureOptions
- describe tls sessionIdContext

De-deduplicate secure context docs:

The secure context options were documented 4 times, making it difficult
to understand where the options come from, where they are supported,
and under what conditions they are used.

The multiple copies were inconsistent and contradictory in their
descriptions of the options, and also inconsistent in whether the
options would be documented at all.

Cut through this gordian knot by linking all APIs that use the
secureContext options to the single source of truth about the options.

PR-URL: https://github.com/nodejs/node/pull/9800


Reviewed-By: Roman Reiss <me@silverwind.io>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>