Improve error message for insufficient number/format of arguments

[teobais]

No Unit found is not descriptive at all.

We should at least make that error message more clear for cases like:

• "75kg" instead of "75 kg"

Our assumption for parsing a compound quantity is that there will be a space character between the value and the unit

[keilw]

I don't know if we'd get any more than Exception in thread "main" java.lang.NumberFormatException: For input string: "100.95" which the JDK Integer class gives when trying to parse a decimal string. The "75 kg" would require the correct value after it was parsed, we cannot assume or construct that in this particular situation, but showing all or the relevant section of that compound string looks doable.

[somayaj]

Hi, can this be assigned to me? Will be willing to contribute. Also, a code pointer. thx