context: model states & auto-(re)connect

this allows UIs to visualize the state (e.g. in a statusbar) or more specifically handle scenarios where the context breaks and the user needs informing and the ability to retry the connection

to facilitate these use cases a new state property is available that fairly closely matches the internal state_t with the added functionality that the Context state is also Connecting before we have an m_context internally.

additionally a new autoConnecting property is available to track the process of internal auto connect behavior on context loss. this is an overarching state in which all other states may appear but may be ignored in the UI on account of possibly being transient