Replace db specific database.ssl_mode config options with a semantic config option 'use.secure.connections'

Recently we enabled that connectors provide config options, validation and docs for the pass-through config options to prefer, enforce or disable secure connections between Debezium and the datastore.
Currently the JDBC driver options might have different name and different options for the different connectors.

Those config options should be aligned over the different (applicable) connectors and replaced with a semantic config option, for example use.secure.connections which can have 3 or more options, eg. auto/prefer --> tries to connect via secure connection but falls back to insecure when no secure connection can be established ; enforce --> tries secure connection and fails when secure connection cannot be established ; disable --> don't use secure connections at all ; strict can be added later --> enforce secure connection including cert validation (requires comprehensive docs to manage certs and preparations in the UI).

Then map to connector specific options (e.g. database.ssl_mode etc) in the *ConnectorConfig implementations.

With this change it should also not be possible/allowed anymore to configure the connector specific options (e.g. database.ssl_mode etc).