Add region actor

[NotBad4U]

• Define a ID
• Store the player and energy in a Set.
• Create the initial state with unique ID for each entities
• calculate the AOI of a player
• Initiate a new game stage
• Notify the last world state at the journal
• store the event in a DB (file) : create, destroy, move (optional)
• Check if the player move from a region to another one. If it is then you send a transfer message to the proxy (That need some requirement of Add arbitrator actor #19: moved player message)

[NotBad4U]

Updated the TODO with the merge of #26

[NotBad4U]

Updated with the merge of #31 and #29
Do we keep the item " store the event in a DB (file) : create, destroy, move (optional)" in this list or we create an other issue and close this one ?

[d-plaindoux]

AFAIC This should be managed in another issue.