Devise a method for normalizing storage of different units in a packed Long

[kevincianfarini]

Similar to how Duration stores a value in either milliseconds or nanoseconds.

[kevincianfarini]

This will be particularly helpful for Area and Volume. Their scales are much more steep than other SI units' -- Area scales by 1,000,000 between each order of magnitude, for example. Sacrificing 2 bits of storage capacity allows us to model the following for area with gradually degrading precision:

1. 2.3km² at μm² precision
2. 2.3Mm² at mm² precision
3. 230Mm² at cm² precision
4. 2.3Gm² at m² precision

[kevincianfarini]

Volume could have the following ranges:

1. 2.3 m³ at μm³ precision.
2. 2.3 km³ at mm³ precision.
3. 2.3 Mm³ at m³ precision.
4. 2.3 Gm³ at km³ precision.

[kevincianfarini]

This is required to even attempt #51. Before starting we should determine if representing different ranges of values provides a satisfying result, or if #55 would provide a better result.