tmf: Support importing archives from directories and archives (nested

tmf: Support importing archives from directories and archives (nested
archives)

This features complements the existing import wizard so that the
archives present in the selected source (directory or archive) get
extracted automatically.

Change-Id: Ia30ca927c4634e092e674b8d36b1d3846d4061b6
Signed-off-by: Marc-Andre Laperle <marc-andre.laperle@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/44965
Reviewed-by: Hudson CI
Reviewed-by: Bernd Hufmann <bernd.hufmann@ericsson.com>
Tested-by: Bernd Hufmann <bernd.hufmann@ericsson.com>
Reviewed-by: Patrick Tasse <patrick.tasse@gmail.com>
Tested-by: Patrick Tasse <patrick.tasse@gmail.com>