Fixes issue with sub collection for pool members (#53955)

Refactors main() function and module manager in multiple modules in line with recent changes
Adds variable types to docs
Refactors unit tests to remove deprecated parameters

test/units/modules/network/f5/test_bigip_device_facts.py

@@ -103,9 +103,11 @@ class TestManager(unittest.TestCase):
     def test_get_trunk_facts(self, *args):
         set_module_args(dict(
             gather_subset=['virtual-addresses'],
-            password='password',
-            server='localhost',
-            user='admin'
+            provider=dict(
+                server='localhost',
+                password='password',
+                user='admin'
+            )
         ))
 
         fixture1 = load_fixture('load_ltm_virtual_address_collection_1.json')