fix: TokenOptionAllocation payment should come from grantee instead of recipient

Author: Detoo

src/TokenOptionAllocation.sol

@@ -143,10 +143,9 @@ contract TokenOptionAllocation is BaseAllocation {
         uint256 paymentAmount = getPaymentAmount(_tokensToExercise);
         if(paymentAmount == 0) revert MetaVesT_TooSmallAmount();
 
-        address recipient = getRecipient();
-        safeTransferFrom(paymentToken, recipient, getAuthority(), paymentAmount);
+        safeTransferFrom(paymentToken, grantee, getAuthority(), paymentAmount);
         tokensExercised += _tokensToExercise;
-        emit MetaVesT_TokenOptionExercised(grantee, recipient, _tokensToExercise, paymentAmount);
+        emit MetaVesT_TokenOptionExercised(grantee, getRecipient(), _tokensToExercise, paymentAmount);
     }
 
     /// @notice Allows the controller to terminate the TokenOptionAllocation