Fix VESPA_target_* global attribute

[BaptisteCecconi]

Currently, the VESPA_target_name and VESPA_target_class attributes are a text string, with # separator.

Example:

VESPA_target_name = "Jupiter#Io"
VESPA_target_class = "planet#satellite"

We should transform this into a list of terms:

VESPA_target_name = ["Jupiter", "Io"]
VESPA_target_class = ["planet", "satellite"]

[BaptisteCecconi]

The current implementation also adds an extra # at the end of VESPA_target_name when there should be only Jupiter (and then satellite should not be in target class either):

VESPA_target_name = "Jupiter#"
VESPA_target_class = "planet#satellite"