Handle Unmapped Faker Entity Types

[Robbie-Palmer]

Suggested by @melmatlis in #50 (comment)

To avoid the library breaking when faker adds new entity types

"Perhaps we can add to the faker_to_presidio mapping an additional default value 'other' for cases when a new unmapped key appears, then the mapping will become:"

                span.type = self.faker_to_presidio_entity_type.get(span.type,'other')

These unknown types would also need tracked and replaced in the template