Update BF-LU to update validation for entity references in patterns

[vishwacsena]

Fixing an issue that @chrimc62 found via generated dialogs.

[chrimc62]

[munozemilio]

The same operation is done for all properties. This could be replaced by a for going over an array

[munozemilio]

Small code improvement proposed

[munozemilio]

@vishwac could you please add details on the fix priority and issue

[vishwacsena]

@munozemilio sure. LUIS recently relaxed the requirement around uniqueness of entity names. Prior to build, all entity names across their scope (including child entities) need to be unique across the entire application.

With recent changes to LUIS, entity names need to be unique under the immediate parent scope. This means I can have a global entity foo and a child entity with the same name.

Without this fix, BF-LU parser will disallow child entities with same name as a different globally scoped entity. e.g.

@ list foo
@ ml parent = 
    - @ foo foo

# test
- this is a pattern with {foo}