Document current design and implementation of local state management

[oxcabe]

Description

We are looking to document the current design and implementation of state.

The reasons:

• to have a reference providing a clearer view, given the complexity of the system.
• to thoroughly identify the underlying issues of the current implementation
• to use as a comparing base for the upcoming improvement proposals

What to document

• Dependencies in use related to state management
• Project-specific design of the state, accessors and mutators
• Communication between view and state
• Uses of deprecated functionality