Connections settings tab

[whymarrh]

Refs #4703, #6904, #6955

This PR does a few things:

• This PR removes the Share Address notification added in Privacy mode as default #6904
• This PR removes the Privacy Mode toggle from settings
• This PR introduces a new Connections tab in settings that allows users to add and review sites that have access to their accounts
• This PR makes the list of connected sites persistent across MetaMask reloads

Some context:

• As of Privacy mode as default #6904 (released in v7.0.0) Privacy Mode is on by default for all new users
• Any existing users have/will be migrated to Privacy Mode
• Privacy Mode means that sites must request account access à la EIP-1102 (or, as of this PR, they can be explicitly added)

Screenshots

Some finer details:

• The input for adding a site doesn't currently enforce a valid domain
• The input for adding a site IS pre-populated in the popup (via the browser action) with the active tab's origin

[danjm]

First question I have is whether we are certain we want to persist all connect request approvals? This will be a change in user experience. Might there be some users who like the default of these not being persisted?

[whymarrh]

1. I feel like it is an improvement in the UX (that is, I think it is a good idea and I stand by it)
2. I can drop dd29ae6 if we don't, no sweat

[Gudahtt]

First question I have is whether we are certain we want to persist all connect request approvals? This will be a change in user experience. Might there be some users who like the default of these not being persisted?

Good point. While I'm sure most users would prefer them be persisted, there are sure to be those that prefer nothing to be saved between sessions.

The ideal solution might be a toggle, perhaps? One that defaults to persisting connections. I'm not sure how important that'd be to include in this release though. 🤔

[whymarrh]

The ideal solution might be a toggle, perhaps? One that defaults to persisting connections. I'm not sure how important that'd be to include in this release though. 🤔

I don't think that's quite ideal. I think we can comfortably pick one way and stick with it.

[danjm]

First question I have is whether we are certain we want to persist all connect request approvals? This will be a change in user experience. Might there be some users who like the default of these not being persisted?

I guess the remove all button is there for users who really care

[Gudahtt]

I don't think that's quite ideal. I think we can comfortably pick one way and stick with it.

I was thinking of it like an "Incognito mode". Certainly nothing we need right now though, granted.

[Gudahtt]

Looks good! I noticed a few stray props that should be removed, but everything's good aside from that.