This reverts commit f1fd63205e.

* Zone object no longer treats them special, some tests needed adjusting
  b/c of this, some provider's tests may also need adjusting, though
  they should not plan changes since they won't (yet) have
  SUPPORTS_ROOT_NS
* _process_desired_zone filters and warns when not supported
* YamlProvider supports them
* TinyDnsBaseSource supports them

* spelling: ancillary
* spelling: antarctica
* spelling: australia
* spelling: authentication
* spelling: continental
* spelling: constructor
* spelling: conversion
* spelling: creation
* spelling: doesn't
* spelling: easily
* spelling: efficiently
* spelling: equivalent
* spelling: essentially
* spelling: everything
* spelling: exactly
* spelling: be
* spelling: expensive
* spelling: supports
* spelling: healthcheck
* spelling: immediately
* spelling: ignored
* spelling: invocation
* spelling: itself
* spelling: leftovers
* spelling: missing
* spelling: natural
* spelling: nonexistent
* spelling: peculiarities
* spelling: pointing

This change hit a line length limitation, so I'm wrapping it and
adding a period which appears to match local style...

* spelling: quicker
* spelling: response
* spelling: requested
* spelling: redirect
* spelling: traffic
* spelling: unknown
* spelling: uploaded
* spelling: useful
* spelling: separately
* spelling: zone

- adds lenient flag to Record.new, problems during validation are just
  warnings if it's true
- target populate calls during the plan phase pass lenient=True
- make all of the provider.populate call logging consistent including both
  target and lenient
- add source=self to Record.new in a few places that were missing it

Fixes an issue where we'd be looking for custom healthcheck config on the
existing record object (from the provider) which would never have a custom
setup. Instead looking at desired lets us find what's actually configured to be
the case