Deprecate CoreEnvironment.Builder methods that take builders

Suggested release note text:

The `ClusterEnvironment.Builder` methods that take a `Builder` are deprecated in favor of the overloads that take a `Consumer<Builder>`.

For example, `ioConfig(IoConfig.Builder)` is deprecated in favor of `ioConfig(Consumer<IoConfig.Builder>)`.

The methods that take a `Consumer<Builder>` are preferable because they allow customizing the config without clobbering the previous values.