Add ability to specify host/port to use when connecting to Snowflake

[jwnorma]

Is your feature request related to a problem? Please describe.
We can't connect directly to Snowflake when running a build from CI / CD service, but instead need to connect through a bastion server using SSH tunneling.

We'd like to setup an integration test that connects to Snowflake in our app that uses the pipelinewise-target-snowflake target, and can't currently b/c configuring the port isn't possible.

Describe the solution you'd like
The snowflake-connector-python library now allows for the host and port to be configured. It would be great if that could be an option for the target config file, and passed through when establishing the snowflake connection

https://github.com/snowflakedb/snowflake-connector-python/blob/main/src/snowflake/connector/connection.py#L930

https://github.com/transferwise/pipelinewise-target-snowflake/blob/master/target_snowflake/db_sync.py#L294

Describe alternatives you've considered

There's not a great alternative, other than running our CI/CD pipeline from another tool or running integration / end-to-end tests remotely, but that requires a lot of additional process coordination and infrastructure to manage.

Additional context

Currently the host gets inferred by the snowflake connection library by passing in the account name and/or region https://github.com/transferwise/pipelinewise-target-snowflake/blob/master/README.md?plain=1#L129

https://github.com/snowflakedb/snowflake-connector-python/blob/main/src/snowflake/connector/util_text.py#L236