Add validation check that primary_key, alternate_keys and sequence_key cannot be sdtype categorical

[npatki]

Problem Description

The initial version of SDV 1.0 will not support the case where primary key, alternate keys or sequence key are type categorical. Let's check for those cases during the metadata validation.

Expected Error

# primary key case
Error: The primary_key ('user_id') cannot be type 'categorical'.

# alternate keys
Error: The alternate_keys ('email', 'phone_number') cannot be type 'categorical'

# sequence keys
Error: The sequence_key ('patient_id') cannot be type 'categorical')

Additional context

Relevant methods to check are:

• validate()
• set_primary_key()
• add_alternate_keys()
• set_sequence_key()