rdb: acl: handle multiple descriptions when adding ACLs

[Mia-Cross]

Following up #3597

Now that we have the possibility to run a single command with several positional arguments, we can convert the single description to a list of descriptions and have a custom description for each rule in the same command.

Command : scw rdb acl add 1.1.1.1 2.2.2.2 3.3.3.3 descriptions.0=first descriptions.1=second descriptions.3=third
Should set :

• rule 1 = {ip: 1.1.1.1, description: first}
• rule 2 = {ip: 2.2.2.2, description: second}
• rule 1 = {ip: 3.3.3.3, description: third}