account_cash_deposit: Add a new type : transfer between cash journal

[TeoGoddet]

Is your feature request related to a problem?
We have a central stock of money (materialized as a cash journal) and a lot of cash journals that can request money from this stock.
We would like to manage the stock and the requests using this module.

Describe the solution you'd like
We would need a transfer action_type that would allow us to request some cash to be moved from a journal to another (we would use tier validation)

What would you think of such thing ?

Main design choice I see is the accounting move or moves, two choice.

• make a move from cash account A to cash account B (but then in witch journal)
• make two move (A to interbank then interbank to B) and reconcile them