Add wallet locking

[JonRay15]

Story

As a user I want my wallet to have a lock mode, which can be triggered manually and automatically So that I am protected from leaving my laptop open

Acceptance Criteria

• [ ] There is a button somewhere to lock my wallet manually (see Metamask screenshot)
• [ ] There is an automatic lock feature that will lock the wallet after a period of inactivity
• [ ] There is a setting to specify the duration of that timeout (including setting to "never")

Tasks

• [ ] Detailed sketch
• [ ] Visual design
• [ ] Frontend tasks:
  • [ ] Implement UI
  • [ ] Integrate with backend
  • [ ] Write unit tests
• [ ] Backend tasks:
  • [ ] TBC
  • [ ] Write unit tests
• [ ] Write end to end tests
• [ ] Code review
• [ ] Team verify acceptance criteria met
• [ ] Exploratory QA testing
• [ ] Capture bugs and new edge cases in tickets (this one or new TBD)
• [ ] Write automated regression tests for the A/Cs (expanding on A/Cs where possible)
• [ ] Add story and A/Cs to spec doc
• [ ] Review with stakeholders
• [ ] Release

Sketch

Notes