feat: allow replacing protocol files when importing

[ecormany]

Overview

As a user who frequently makes changes to Python protocols, when I import the modified protocol into the app, I would like the option to replace the previous version. This would help keep the Protocols list tidy and make the Run Protocol on Robot slide-out more useful (currently it is nearly impossible to pick the correct version of a protocol from the slide-out when there are many protocols with the same name).

Implementation details

Envisioning:

• A "Do you want to replace [protocol-name]?" modal when importing a protocol that matches an existing protocol (by filename and/or other criteria)
• Possibly a setting to always replace, never replace, ask each time

Design

Acceptance criteria

[ecormany]

Will consider this for AUTH-1736.