Support numeric sort in ByParam

Support numeric sort in ByParam

With this commit ByParam takes into account a type of a value under a
key. If both values are numeric then they're coerced into float64 and
then get compared.
If any value isn't numeric, for example it's nil or string, then both
values coerced into string and get compared as strings
(lexicographicaly)

Nil values are always sent to the end.

Numeric values confirm to any type listed below:
uint8, uint16, uint32, uint64, int, int8, int16, int32, int64, float32, float64

Closes #5305