Remove references to registrar from code

...llers/admin/course_editions/project_imports_controller.rb

app/controllers/companies/role_invitations_controller.rb

app/controllers/companies/roles_controller.rb

app/controllers/companies_controller.rb

app/controllers/dashboards_controller.rb

app/models/company.rb

app/models/concerns/user_concerns/associatable.rb

app/views/admin/companies/_form.html.erb

app/views/admin/companies/index.csv.erb

app/views/admin/companies/index.xlsx.axlsx

app/views/admin/companies/index/_table.html.erb

app/views/companies/index.html.erb

app/views/companies/modals/_modal_join_company.html.erb

app/views/dashboards/show/_organizations.html.erb

app/views/generic_projects/index.html.erb

app/views/offerers/show.html.erb

config/locales/models/company/en.yml

config/locales/models/company/nl.yml

config/locales/models/role/en.yml

config/locales/models/role/nl.yml