Migrating tin_matched field from enum to boolean

The tin_matched field has been migrated from being an enum with values NO_MATCH or EXACT to a boolean to reduce confusion.

tin_matched was previously an enum to align more closely with the business_name_match and business_address_match, but since there is no SIMILAR match for the tin_matched field, it makes more sense to treat it as a boolean - since the TIN is either a match by the IRS or not.