Handle signed entity types in client

[jpraynaud]

Issue

Adapt the client to handle multiple signed entity types. For this, we will use a specific cli sub command for each signed entity type.

To do

• Create the sub-command for Cardano Immutable Files Full in client #895
• Create the sub-command for Mithril Stake Distribution in client #896
• Update client documentation #897

Parent issue

#780