refactor(core): Guarantee system accounts existence for programs

[ekovalev]

Resolves #3924.

The idea is to separate the notion of value ownership/transfer by actors in Actor space from the underlying system accounts management level (e.g. Substrate's frame-system and balances pallets).
Programs (a.k.a. actors) should not care about their "wallets" implementation details and whether or not they require things like existential deposits to stay alive or have to respect limits on transferred value amounts imposed by the system level. Instead, the protocol must guarantee an invariant that for any active program there always is an account able to store any amount of value at any point throughout the program's lifetime.

This change, once implemented, renders useless numerous checks of a value validity in balances transfers - any value should be valid for a transfer and not cause program's account removal.

Specifically, the PR implements:

• Charging the existential deposit to user's balance at the time of a program creation in Gear::upload_program and Gear::create_program extrinsics
  • 2 tests
• Validating that existential deposit can be charged to a program's balance in case another program being created using the gr_create_program syscall (by decrementing the value counter) and further actual transfer of the ED in JournalNote::StoreNewPrograms handler
  • Track the case when code does not exist, so that refund must be made
  • 2 tests
• The existential deposit is transferred to the program inheritor upon the gr_exit syscall (program deactivation)
  • 1 test
• Removal of value limits (various check_value) in all send-like extrinsics and all backend send-like syscalls
  • 2 tests: extrinsics/syscalls (for syscalls could be implemented as core-processor/ext unit tests)
• Ensures all transfers in the system are made with Existence::AllowDeath requirements (since the platform guarantees the account will not die as long as the program remains in active state)
• Implements migrations to deposit ED from Treasury for each program that already exists in storage
  • try-runtime tests that after migrations all program that are in "Active" status have accounts with at least ED on them
• Fix existing tests

[breathx]

Seems ready to be reviewed once fixed benches?

[ekovalev]

Seems ready to be reviewed once fixed benches?

Yes, pretty much.

[ukint-vs]

lgtm.

[NikVolf]

merge master @ekovalev ?

[NikVolf]

@breathx final thoughts?

[breathx]

tests to be re-reviewed once applied suggested changes

otherwise well done

[breathx]

Im only worried now about match error branches and panics. Otherwise seems awesome 👍🏻 great job

[breathx]

@techraed kindly asking you to double check the changes and my comments above

[techraed]

Awesome!

I remember we agreed to use locks and to introduce integrational test, which tests that underlying Currency implementor locks & account existence invariants works as expected.

So, could you, please, introduce the test in this PR?