Commented Issue: Distance.Parse is inconsistant with invalid input [24937]

Distance.Parse throws an exception when a number with an unrecognized unit is entered:

```
Distance.Parse("3 this should not be valid");
```

This is fine, but if the number is removed:

```
Distance.Parse("this should not be valid");
```

Then the function returns a Distance object set to "0 ft" and IsInvalid=false.

Invalid text without a number should throw an exception.
Comments: Associated with changeset 73712: Fixed #24937: Distance.Parse is inconsistant with invalid input