feat(gtest): Improve value and ED managment

[ByteNacked]

Release notes:

• Improved value and ED management in gtest. Programs now spend gas during execution and charge ED upon creation.
• Refactored gtest, adding separate Accounts and Actors stores.
• Removed the Program::mint method from gtest; users should now use System::transaction to top up a program's balance.

@reviewer-or-team

[ByteNacked]

TODO:

• Fix rest tests
• Add additional checks in balance module, improve panic logs

[ByteNacked]

Fixed all tests

[techraed]

You need to rebase to master

[techraed]

Excellent work ⭐
Love it how gtest looks now.

There are some tiny correction has to be done. Also very important:

1. actors and accounts storages must be cleaned when System is dropped (see drop impl for the System)
2. I suggest removing Program::mint_to. Actually System::transfer is the most right way to mint balance to the program. Also I'd remove ED check from the ExtManager::mint_to, because 1) the Account::increase already does the op the proper way (if account exists then allows minting value lt ED), 2) the method would be used only for users, not programs (see 1).
3. In accordance to 2 need to add check that id is the user in System::mint_to.

[techraed]

🔥