This commit adds the pg autoscaler support.
The structure for pool definition has now two additional attributes
`pg_autoscale_mode` and `target_size_ratio`, eg:
```
test:
name: "test"
pg_num: "{{ osd_pool_default_pg_num }}"
pgp_num: "{{ osd_pool_default_pg_num }}"
rule_name: "replicated_rule"
application: "rbd"
type: 1
erasure_profile: ""
expected_num_objects: ""
size: "{{ osd_pool_default_size }}"
min_size: "{{ osd_pool_default_min_size }}"
pg_autoscale_mode: False
target_size_ratio": 0.1
```
when `pg_autoscale_mode` is `True` user has to set a decent value in
`target_size_ratio`.
Given that it's a new feature, it's still disabled by default.
Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1782253
Signed-off-by: Guillaume Abrioux <gabrioux@redhat.com>
Guillaume Abrioux