Shorten name of WithdrawAmountGreaterThanWithdrawableAmount error

[PaulRBerg]

As @IaroslavMazur pointed out in his audit report conducted in March 2023, the name of this custom error is long:

https://github.com/sablierhq/v2-core/blob/2b71d0762706ad04cdad58e37d2c6db0b6274496/src/libraries/Errors.sol#L82-L84

He suggested renaming the error to AmountTooBig, but I did not like this wording because it can easily be confused with something else, e.g. an overflow, so I ended up brushing the issue aside.

In the meantime, I have stumbled upon the term "overdraw", which is perfect given the context of the withdraw function; let me show you the definition from Cambridge Dictionary:

to take more money out of your bank account than the account contains

Therefore, we should rename the error like this:

error SablierV2Lockup_Overdraw

[IaroslavMazur]

Indeed, "overdraw" looks like the perfect fit for the "trying to withdraw too much" scenario.

Great finding, @PaulRBerg!