[test] Enable storage limit for emulator backend

[m-Peter]

Description

This will make the testing environment behave more similar to a development/testnet/mainnet environment.

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[m-Peter]

Note: I will rework this to be enabled with a pragma, instead of enabling it by default.
That is actually requires quite some changes, and I do not see any benefit. I think it is better to have the storage limit always enabled, as users can easily mint/burn flows, to test out scenarios with storage.

[SupunS]

Is there a way to set the storage limit for tests? Or does it use a default value always?

[m-Peter]

The default value is taken from here: https://github.com/onflow/flow-go/blob/47e239c3b505d75b41c3cb92666eba56d541c8a0/fvm/bootstrap.go#L26-L28, when using emulator.WithStorageLimitEnabled(true).
We can specify a different value with emulator.WithMinimumStorageReservation(), but this cannot be changed once the emulator is up and running. That's why I went with the default value, to keep parity with the rest of the environments.

[SupunS]

I feel these small value differences in account balances could be annoying for users when writing tests.
(Also not sure why it changes the account balances when the storage limit is enabled).

So maybe we should have this disabled by default (to make the simple use-cases simple), and allow developers to enable it only if they need it.

[m-Peter]

I feel these small value differences in account balances could be annoying for users when writing tests.

That' a good point 👍

(Also not sure why it changes the account balances when the storage limit is enabled).

The emulator.WithStorageLimitEnabled(true) means that every account has to be created with the minimum storage reservation (0.001 FLOW), otherwise the account would break the storage limit constraint.

So maybe we should have this disabled by default (to make the simple use-cases simple), and allow developers to enable it only if they need it.

Sounds good, I will try the approach where this is enabled per test file, with a pragma directive (#storageLimitEnabled).

[m-Peter]

@SupunS I have reworked this to use a Cadence pragma directive, instead of enabling it by default. Take a look when you can, and let me know what you think 🙏