Change "Range" with the actual variables in the storage structs

[andreivladbrg]

In this PR #220 we faced some issues with the well known: "Stack too deep" error, and because of that we added a couple of structs to get rid of some function parameters. One of them is the Range struct:

https://github.com/sablierhq/v2-core/blob/55a4d2ed225131247c97dd5ed352c44d755007eb/src/types/DataTypes.sol#L66-L70

Which has the purpose of replacing these variables from create function:

    uint40 startTime; 
    uint40 cliffTime; 
    uint40 endTime; 

There is an issue with it: @PaulRBerg decided to also use it in the storage struct and the gas has increased with 21740 in {SablierV2LockupLinear-createWithRange}, the time variables are not tight packed anymore.
https://github.com/sablierhq/v2-core/blob/55a4d2ed225131247c97dd5ed352c44d755007eb/src/types/DataTypes.sol#L81-L88

Gas comparison

With Range struct

Linear

Pro

Without Range struct

Linear

Pro

My suggestion is to continue using the Range struct as a function parameter but to remove it from the storage struct. The downside is that the refactor will take time and I don't know if we can delay more, @razgraf needs the contracts for the app development.

[PaulRBerg]

Thank you for opening this discussion, Andrei.

I am sympathetic to your proposal, since 20k gas is non-negligible. Let me sleep more on this idea before we make a final decision - in the short term, we will pass on the contracts to the frontend team as they are now so they can start the refactor of the subgraph.

[PaulRBerg]

Locking, as we implemented this in #334.