Adds a factory function for getting REST api tools (#21423)

I plan on converting most all f5 modules to use the rest api, so
this is part of that conversion. it adds a factory method to get
the various rest management root apis provided in the f5 sdk

test/compile/python2.4-skip.txt

@@ -46,6 +46,7 @@
 /lib/ansible/module_utils/vmware.py
 /lib/ansible/module_utils/netconf.py
 /lib/ansible/module_utils/junos.py
+/lib/ansible/module_utils/f5.py
 /lib/ansible/parsing/
 /lib/ansible/playbook/
 /lib/ansible/plugins/