Settings form for hide_bic and hide_billing

With the extraction of SEPAPP from the SEPA extension, the settings form for the payment processor settings got lost.
Currently the settings for hide_bic and hide_billing have to be entered manually into the table civicrm_setting.

It would be nice to have a settings form to enter these settings via the UI.

Or, as a simple alternative, these settings could be entered automatically into the database during installation of SEPAPP (since I cannot imagine any use case to change these settings):

INSERT INTO civicrm_setting (name, value, domain_id, contact_id, is_domain, component_id, created_date, created_id) VALUES ('pp_hide_bic', 's:1:"1";', '1', NULL, '1', NULL, '2021-04-09 11:07:08', '2');
INSERT INTO civicrm_setting (name, value, domain_id, contact_id, is_domain, component_id, created_date, created_id) VALUES ('pp_hide_billing', 's:1:"1";', '1', NULL, '1', NULL, '2021-04-09 11:07:08', '2');

No files or tests are named. Start by locating SEPAPP's installation handling and the payment processor settings entry point, then inspect how civicrm_setting values are registered and displayed. Done means hide_bic and hide_billing can be managed through the UI or are reliably created during installation, with the chosen approach documented and verified.