Feature/76 edit view

[nbarlowATI]

• Some changes (e.g. frontend Dockerfile) merged in from main.
• Add new lock_uuid charfield to AssuranceCase model (replacing boolean field editable).
• In CaseContainer.js generate a new uuid and store it in both the state and the browser's sessionData (so it is maintained with "refresh").
• Add some logic in CaseContainer to allow user to:
  • enable edit mode if the case's lock_uuid is currently null,
  • disable edit mode if the case's lock_uuid is currently this user's session_id
  • override another user's edit mode if the case's lock_uuid is a non-null value that is not the current session_id
• Add an event listener so lock_uuid will be reset to null if the browser tab is closed.

[coveralls]

Pull Request Test Coverage Report for Build 2207266877

• 0 of 5 (100.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.2%) to 88.377%

---

Totals
Change from base Build 2202258230:	0.2%
Covered Lines:	920
Relevant Lines:	1041

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 2219301662

• 5 of 5 (100.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.05%) to 88.207%

---

Totals
Change from base Build 2202258230:	0.05%
Covered Lines:	905
Relevant Lines:	1026

---

💛 - Coveralls

[mhauru]

This is great! Nice and elegant and robust seeming. I had one question about possible race conditions, can be merged as-is though.