Deprecate obsolete driver options

With the completion of PHPC-1288, the following driver options become obsolete and can be deprecated:

• allow_invalid_hostname
• weak_cert_validation
• pem_file
• pem_pwd
• ca_file

The deprecation message should advise users to use the corresponding canonical URI option instead.

The following driver options have been deprecated according to the documentation, but don't yet trigger a deprecation warning:

• allow_self_signed
• local_cert
• passphrase
• cafile
• capath
• context

The deprecation message for these options should also advise users to use URI options instead.

This leaves the following undeprecated driver options:

• crl_file
• ca_dir