Modified return value for ipavault module.

The ipavault module was returning a single string value when retrieving
data. To keep consistency with other modules, it should return a dict
with the `data` variable in it.

This change modifies the result of ipavault to be a dict and also fixes
relevant tests, examples and documentation.

playbooks/vault/retrive-data-asymmetric-vault.yml

@@ -14,4 +14,4 @@
         state: retrieved
       register: result
     - debug:
-       msg: "Data: {{ result.data }}"
+       msg: "Data: {{ result.vault.data }}"