Type transactions model

This MR :

• sets the types to the properties of a Transaction. Defining strictly the properties had the consequence to :
  • set by default the transaction type to 'UNKNOWN_TYPE', which was not the case before and lead to failed tests (this is why they are now fixed)
  • made tsc yell for the diffTransations functions, that a Partial<Transaction> could have a rawLabel and amount undefined, which is not true, so I had to force the type to Transactions (like for accounts).
• defines the type of method parameters of Transactions model.