moved get_pds_data() block to Role::PDS - don't need 'with' followed by 'with' any more in Validate; made logo img-responsive class to enable dynamic resize; tt layout rearrangements
removed params & config tokens from before_template hook (automatic anyway); renamed search() to to disambiguate from 'var'; moved content of _validate_form() & _validate_nhs_number() back into routes (only 2 lines each); Path::Tiny in Role::PDS
fixed session storage and retrieval failure in Role::PDS - needed to use read() method to access and {data} key to store; completed all functions - version ready for testing with HILIS4
