pipeline: outputs: kinesis: add custom port configuration option

[azalio]

This commit introduces a new 'port' configuration option for the Kinesis output plugin. This enhancement allows users to specify a custom TCP port for connecting to the Kinesis Streams service, providing greater flexibility in network configurations.

Key changes:

• Added 'port' option to the configuration documentation
• Updated the Kinesis output plugin to support custom port connections
• Maintained default behavior (port 443) when no custom port is specified

This feature is particularly useful in environments where non-standard ports are required due to network policies or when connecting through proxies that use alternative ports.

The change is backwards compatible, as existing configurations without a specified port will continue to use the default port 443.