Allow to create a machine as deployed from the UI

[webteam-app]

Bug originally filed by ack at https://bugs.launchpad.net/bugs/1940909

As part of the brownfield work, it is now possible to create machines in maas that are marked as "deployed" even if they haven't been deployed from maas.

This is done by passing deployed=True in the create method (both in the API and the UI).

The UI should provide a way to pass the flag. Currently this is the only change needed in the create form, all other constraints/validation stay the same.

[petermakowski]

This is blocked until "add machine" form is reworked: https://bugs.launchpad.net/maas/+bug/1940909#yui_3_10_3_1_1650978387769_1906
https://bugs.launchpad.net/maas/+bug/1887699

[Caleb-Ellis]

Closing as this will be fixed as part of #1884