Add Connected Accounts modal

[whymarrh]

This PR implements the Connected Accounts modal designs.

Screenshots

Screenshots of the unconnected flow

[rekmarks]

Looks great!

In addition to the inline suggestion, the way we identify the Primary account label is not correct. The permitted accounts are no longer ordered in the permissions state. They have to be sorted by preferences.identities[account].lastSelected to identify which one is first. That's what we do before sending them to the dapp.

Currently, the Primary label is identified by whatever account is first in the permissions state.

Edit: We may also want to consider the name Primary. I was talking to @jennypollack about this earlier, and we want to encourage dapps to pay no attention to the order of the accounts returned from eth_accounts or accountsChanged, and let the dapp handle what the "primary" account is, if any. On the other hand, I'm not sure what that name should be. "Maybe the only account that the dapp will acknowledge until to switch to it in the MetaMask popup UI while browsing the dapp" doesn't exactly roll off the tongue.

[Gudahtt]

we want to encourage dapps to pay no attention to the order of the accounts returned

I'm not sure we do want to do this, and I don't think it's something we can reasonably accomplish. A lot of dapps just want to deal with a single account, not a list, and I don't see why we'd object to this.

[whymarrh]

I'm just addressing the portal comment now, everything else should be good

[brad-decker]

LGTM, just a question for learnin' reasons.

[whymarrh]

@Gudahtt I moved the options into a tooltip in 76b80cc

Changes made!

[Gudahtt]

Looks good so far! I haven't reviewed the styles in detail yet, but I'll do that shortly. The account sort order is the only blocker.

[whymarrh]

There's a single outstanding (small) issue here where switching accounts via the options list will keep the tooltip open. I'm not sure if there's an option to configure both hiding the tooltip when clicked and to have it be interactive.

[Gudahtt]

Two outstanding issues remain:

• The account options menu is not great. It's weirdly slow to close (feels like almost a second!?), and doesn't close in all cases we'd want it to.
• The sort order of the accounts still isn't quite correct - the secondary order is now dictated by the order of permissions (which isn't supposed to be meaningful) rather the keyring controller order. This would be just a minor nuisance/inconsistency except that it is possible for accounts to have never been selected, so the primary account may still be wrong in some cases.

The first is not a deal-breaker, and the second is a weird edge case, so I think this is fine to merge for now so that design QA can start. I'll address both of these issues in separate PRs.

[Gudahtt]

The account options menu is not great. It's weirdly slow to close (feels like almost a second!?), and doesn't close in all cases we'd want it to.

This has been addressed by #8607

The sort order of the accounts still isn't quite correct - the secondary order is now dictated by the order of permissions (which isn't supposed to be meaningful) rather the keyring controller order. This would be just a minor nuisance/inconsistency except that it is possible for accounts to have never been selected, so the primary account may still be wrong in some cases.

This has been addressed by #8608