Add settings for auto-create unbound (unbacked) memory regions

What is the feature you'd like to have?
For those memory regions that is not backed by file, BN won't create related structures/objects, so we must create it by hand, however it would be nice to got setting (checkbox) to set so it would be done automatically.

Additional Information:
For example in macho __DATA is a dynamic segment, so it may be not presented in the file fully, but get the virtual size bigger than physical, however the binary may use such memory, so BN even render it, but won't create the region, so for example BinaryView won't let to patch such memory.

The issue names no files, tests, or entry points. Start by locating the settings implementation and the code that creates memory regions for unbacked Mach-O segments. Define the setting's scope and verify that enabling it creates patchable regions while preserving existing behavior when disabled.