Feature Req: More helpful disk partition extent suggestions and validation

[DaveWK]

When I set up partitions, it would be nice if it didn't expect me to memorize the partition extents.

IE if my first partition ends at 1052671 then the second partition should be suggested to be created at 1052672 and not at the beginning of the drive and overlapping partition 1.

Additionally, when an install configuration has overlapping extents, the install should politely inform the user that the config probably won't work (but allow the install to proceed for whatever bespoke use case I can't think of that one would want that behaviour)