JBSplitHookContext
Notes:
- 
member: token The token being sent to the split hook.
 - 
member: amount The amount being sent to the split hook, as a fixed point number.
 - 
member: decimals The number of decimals in the amount.
 - 
member: projectId The project the split belongs to.
 - 
member: groupId The group the split belongs to. By convention, this ID is
uint256(uint160(tokenAddress))for payouts and1for reserved tokens. - 
member: split The split which specified the hook.
 
struct JBSplitHookContext {
    address token;
    uint256 amount;
    uint256 decimals;
    uint256 projectId;
    uint256 groupId;
    JBSplit split;
}