WIP: feature: Alert users when form has unsaved changes

[coolprobn]

Description

Add a stimulus controller to track changes in the form and show alert box when user moves away from the current form, either by reloading the page or clicking any other buttons in the application with the use of Turbo Navigation.

Fixes # (issue)

Closes https://github.com/avo-hq/avo/issues/673

Checklist:

• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [ ] I have added tests that prove my fix is effective or that my feature works

Screenshots & recording

https://www.loom.com/share/9bac6ed248014dfdbcc52d76b1973a99?sid=ca6389a5-eda4-41df-a357-e987a3565233

Manual review steps

Feature walkthrough is in the screen share attached above

TODO

• Add tests for the changes