refactor: improve ssl options validation

[zmstone]

improves #191

Previously:

1. if the initial config is invalid, the error message is extremely hard to comprehend because it's a throw without context originated from ssl lib.
2. if trying to set invalid options, the it's a badmatch crash for the caller of set_options

Now:

1. Initial invalid config results with an error with more context invalid_ssl_option
2. Invalid options set from set_options returns an {error, Reason} tuple (with the same context)

see test cases for more details