Remove chat menu item and toggle app switching privacy on by default

[rachelhamlin]

Problem

Combination issue spanning two product areas:

1. Chat + menu—remove an option
2. Profile > Privacy and security—turn a setting ON by default, alter copy

Implementation

• Remove the Scan a QR code option from the chat menu

• Change the copy of Hide content when switching apps to White out Status when switching apps
• Set this toggle to be ON by defautl
  

Acceptance Criteria

• No more scan QR code option in chat menu
• New copy for Privacy and security option
• White out setting is on by default

[churik]

Reason why scannig QR code option in chat menu should be removed:
from @hesterbruikman: it's out of context in chat. I genuinely love the scan anything feature, but in our current tab based UI we don't really have a fitting spot for such a global feature and it leads to an overwhelming nr of options inside chat. Would love to see it make a come back when we move to something like window-based navigation