Add a general operation property 'IsolatedFromAbove' that guarantees that all regions...

Add a general operation property 'IsolatedFromAbove' that guarantees that all regions of a given operation are explicit capture only and will not reference values defined above the enclosing operation. This trait will be useful for applying some of the properties currently attached to Functions to operations, e.g. verifying dominance within a specific operation, enabling multi-threading of certain transformations between different instances, etc.

PiperOrigin-RevId: 251927466