Expression Functions: some aggregate functions do not support byte values

[thomasknoell]

The aggregate expression functions AVG, MEDIAN, STDDEV and SUM do not support byte values as an input data type although this is a valid input data type. Therefore, the following signature needs to be added to the signature list for each of the mentioned functions:

AVG: FdoDataType_Double AVG ([{ALL | DISTINCT}, ] byte_value) MEDIAN: FdoDataType_Double MEDIAN (byte_value) STDDEV: FdoDataType_Double STDDEV ([{ALL | DISTINCT}, ] byte_value) SUM: FdoDataType_Double SUM ([{ALL | DISTINCT}, ] byte_value)