[client] Migrate budget store to typescript and use 'immer' instead of 'updeep'.

This MR migrates the budget store to typescript and to use immer. For this I needed to :

• allow void type for createActionCreator, as we now have actions without parameters (the reset of budget store)
• type correctly assertNonNull
• initialize the budget store from init function (the store used to have a default value, which we don't have anymore).