[x] access control for dashboard page (only logged in user should access dashboard). Other pages like DID management, relationships and dev mode pages can still be accessed without login. https://github.com/trustbloc/edge-agent/issues/330
[x] do not clear wallet user metadata during logout. Maintain all logged-in user metadata in store and make use of state management (ex: vuex) to find current user and fetch records. It will also make integration with EDV simpler.
[x] preserve wallet user metadata like DID comm connections details for subsequent login. Currently we are losing DIDComm connection details after logout.
[x] do not unregister mediator during logout, currently offline message pickup doesn't work between logout & re-login. Also, in current implementation we re-register with mediator during re-login, where issuers/verifiers are still connected to mediator through old connection ID.
[x] multi user support : credentials, connections saved by user, by having different aries instance for each login.