Investigate how PaymentDriver::init and payment init should work

[kamirr]

[kamirr]

Concerns #2116 and #2118

[kamirr]

During the preparation of the draft PR (#2167), a couple issues have surfaced:

1. As of now, initializing the account as receiver-only protected the user from unintentional spending of funds. With payment init made implicit, this is now functionally a non-feature, as any attempt to allocate funds will automatically enable the capability to send funds.
2. PaymentDriver::init will be called on each allocation and invocation of payment fund, and has always been capable of being used this way (i.e. multiple yagna payment init [--sender] [--receiver]). Meaning there are undocumented semantics, that aren't exactly what one would call "initialization". These have been explained in more detail in the last commit of the PR (Add assumption comments).
3. send and receive (: bool) properties of an account can't be simply removed to drop the support for protection mentioned in (1), as it is actually important to differentiate how an account has been initialized. That is, the initialization might do different things depending on those properties and these properties are not just a soft protection for the end-user.

[nieznanysprawiciel]

It seems current version is ok