[5] Account selector, manage accounts and view mode performance on cloud accounts

[startailcoon]

When using the wallet with a cloud account the top right account selector performs poorly.

You can't access manage accounts drop down, nor does it view the "View Mode" button when browsing an account that doesn't belong the the users cloud account (not in the auth store).

Some performance has to be made to enhance the performance of this and the checks of isMyAccount that only triggers when/after a cloud account is logged in (authorized). When wallet times out, the cloud account authorized credentials is no longer available until the next login (authorized).

Tasks

• [ ] Incorporate solution from #2540
• [ ] Replace all instances of AccountStore.isMyAccount
• [ ] Enable Manage Accounts drop-down for cloud accounts
• [ ] Enable "View Mode" for cloud accounts

[sschiessl-bcp]

Would it make sense to abandoned the double code to differentiate between cloud and local wallet and simply have one list-based approach (each entry in the list could have a type property that indicates cloud and localwallet, in typical usage cloud would then always have length == 1, nevertheless it could also have multiple accounts references or added)