Move various state computations from the UI to the NodeModel

[jarolrod]

To enforce clear seperation between the UI and the backend, as well as to begin the removal of any js functions, this shifts the following string construction and state computations from the UI into the NodeModel itself (which is where it belongs)

• formatted verification progress string
• connected state
• synced state
• estimating state
• formatted remaining sync time

These strings and states are now available and reusable wherever they may be needed, instead of needing to be computed by every file which needs that information.

As a rule, the UI should have no computation of any sorts outside of things related to UI specific ideas such as color or sizing; any other computation needs to be strictly done in our backend.