[ETHEREUM-CONTRACTS] remove footgun from CFASuperAppBase

[d10r]

What & Why

The CFA hook afterAgreementTerminated is invoked when a flow to the SuperApp or a flow from the SuperApp is deleted.
The latter case is unexpected for many, because it exists only for the delete callback, not for the create and update callbacks.
For SuperApps creating outgoing flows and implementing this hook without being aware of it (e.g. not checking the sender argument), this creates the risk of unexpected states, unexpected state updates, and of jailing.

How

• invoke onFlowDeleted only for deletion of incoming flows and remove the receiver argument. This breaks existing code using it, which we want in order to make sure the change can't cause unnoticed behaviour change of such contracts.
• invoke a new hook onOutFlowDeleted for deletion of outgoing flows. This allows to specifically handle this case, e.g. to implement sticky streams (don't allow closing by reopening in the hook).

Note: the change is breaking in the sense that code using it and updating the dependency needs to be changed.
Being just a library which is not used by the protocol itself, it's not breaking in the sense that deployed contracts change behaviour.

[github-actions]

Changelog Reminder

Reminder to update the CHANGELOG.md for any of the modified packages in this PR.

• CHANGELOG.md modified
• Double check before merge

[hellwolf]

@d10r can you check if this can address #2069 ?

[d10r]

@d10r can you check if this can address #2069 ?

can do. But that makes the change considerably more breaking. Worth it?

[hellwolf]

@d10r can you check if this can address #2069 ?

can do. But that makes the change considerably more breaking. Worth it?

It seems so.

[github-actions]

XKCD Comic Relif

Link: https://xkcd.com/2043