Detect port forwardings in case of reused docker-DB

[ckunki]

ITDE currently supports CLI parameters to specify port forwardings for database, bucketfs, ssh.

When using ITDE to validate Exasol database in a Docker Container there a two options

Option	Docker Container strategy	Port forwardings
O1	Spawn a new Docker Container	ITDE applies port forwardings from CLI parameters
O2	Reuse an existing Docker Container	(none)

For option O2 the current ticket therefore requests ITDE to detect the port forwardings of the existing container and reuse them, too.