Added password reset feature to teh backoffice

src/backoffice/templates/backoffice/login.html

src/backoffice/templates/registration/change_password.html

...ckoffice/templates/registration/change_password_done.html

src/backoffice/templates/registration/reset_password.html

...ffice/templates/registration/reset_password_complete.html

...office/templates/registration/reset_password_confirm.html

...ackoffice/templates/registration/reset_password_done.html

...backoffice/templates/registration/reset_password_mail.txt

...koffice/templates/registration/reset_password_subject.txt

src/backoffice/urls.py

src/backoffice/views/auth.py