1703: feat hard delete attachments feature

[BCerki]

card: https://app.zenhub.com/workspaces/climate-action-secretariat-60ca4121764d710011481ca2/issues/gh/bcgov/cas-cif/1703

The card is only about hard deleting attachments in the first revision. I think there may be some other cases in which we'd like to hard delete (e.g., deleting an attachment that was uploaded in the same form change) and made a tech debt ticket to investigate: https://app.zenhub.com/workspaces/climate-action-secretariat-60ca4121764d710011481ca2/issues/gh/bcgov/cas-cif/1776

Also, hard deleting attachments as part of discarding a project revision was split into another card: https://app.zenhub.com/workspaces/climate-action-secretariat-60ca4121764d710011481ca2/issues/gh/bcgov/cas-cif/1798

[BCerki]

work completed in https://github.com/bcgov/cas-cif/pull/1835 and tech debt