Refactor parameters of luigi tasks

[ckunki]

Currently luigi tasks are using separate parameters for port specification.

E.g. class DockerDBTestEnvironmentParameter uses 3 separate parameters

    database_port_forward = luigi.OptionalParameter(None, significant=False)
    bucketfs_port_forward = luigi.OptionalParameter(None, significant=False)
    ssh_port_forward = luigi.OptionalParameter(None, significant=False)

The current ticket proposes to combine these parameters into a single parameter of type Ports:

    port_forwards =  JsonPickleParameter(Ports, significant=False)