Field Type Profiles unable to apply to illuminate index sets, this should be allowed

## What?

The "Field Type Profiles" feature is very powerful and very useful. However, it cannot be used with any illuminate index sets. I believe that this reduces the functionality of this feature. A better approach would be to still allow field types to be applied, but disallow illuminate/reserved fields from being set/overridden.

We DO want to encourage users to use illuminate and to use illuminate indices. However, some users will require additional parsing and fields for their use cases. If the user has issues with field types because of dynamic field mappings they will have no way to fix this issue and no way to force a field type when using an illuminate index.

## Why?

While this feature is useful, it is limiting to only have this feature apply to non-illuminate index sets. As we continue to expand our illuminate content, customers will adopt the use of illuminate streams. However, their use cases may require adding additional fields and they may require setting explicit field types.