feat!: report hosts and licenses as facts, not warnings (0.2.0)

get_device_warnings is gone; netOrk names the warnings from facts
(netOrk #1111). get_hypervisor_hosts() reports each host's connection
state, maintenance mode, configuration issues and managing vCenter;
get_licenses() the assigned licenses with the edition key as edition,
never the key itself.

The reach stays: the ESXi driver reports connected as None (a
disconnected host could not have answered), and managed_by only for a
host it reached directly. parse/warnings.py is replaced by
parse/hosts.py and parse/licenses.py.

README.md

@@ -29,7 +29,8 @@ hardware**: see [Harvesting fixtures](#harvesting-fixtures).
 | `get_vm_snapshots`, `create/delete/rollback_vm_snapshot` | ✅ | ✅ | snapshot tree |
 | `get_vm_storage_pools` | ✅ | ✅ | datastores |
 | `get_virtual_networks` | ✅ | ✅ (+ dvPortgroups) | port groups |
-| `get_device_warnings` | ✅ | ✅ | raw `{code, meta}` |
+| `get_hypervisor_hosts` | ✅ | ✅ | connection state, maintenance mode, config issues, managing vCenter |
+| `get_licenses` | ✅ | ✅ | license manager: name and edition key, never the key |
 | `reboot_host` | ✅ (maintenance mode only) | — | `RebootHost_Task` |
 | `create_vm_from_cloud_init`, `destroy_vm`, `get_vm_status` | ✅ | ✅ | see [Provisioning](#provisioning) |
 | `get_network_targets`, `get_image_storages` | ✅ | ✅ | port groups, datastores |
@@ -148,5 +149,9 @@ The MoRef is reported alongside as `moref`.
 hosts. Reporting them on the vCenter would attach their MACs to the wrong
 device. Add a host with `vmware_esxi` to see its NICs.
 
-**Warnings are raw.** `get_device_warnings()` returns `{code, meta}` only;
-what a code means is decided in netOrk's `WARNING_CATALOG`.
+**Facts, not warnings.** The driver names no warnings. `get_hypervisor_hosts()`
+and `get_licenses()` report what the endpoint says; whether a host in
+maintenance mode or the free `esxBasic` edition is a problem is the caller's
+to decide. The ESXi driver reports `connected` as `None` (a disconnected host
+could not have answered) and the managing vCenter's address as `managed_by`;
+under the vCenter driver `managed_by` is `None`, since every host names it.