WIP: Data size interactive

[eAlasdair]

Adds the recreated Data Size interactive for upcoming content on Big Data

Relates to #1182

[eAlasdair]

This was an attempt to recreate and improve upon the proposed data size interactive for use in the field guide. The original implemented two sorting-type games: the first to arrange data units (b, B, KB etc) by size, and the second to match real-world examples to the sizes they likely fit into. From what I can remember and what I now think, these are the thoughts we had about it:

• We liked the idea of ordering the data units by size
• We liked the idea of offering real-world comparisons
• The comparisons used were sometimes ambiguous or hard to understand
• You couldn't really appreciate the scale (size) of the data while using it
• We decided to stop at EB (rather than ZB)

The current state of the PR interactive is a working arrange-data-units-by-size phase and a work in progress of a match-examples-to-the-size phase. Earlier commits include attempts to completely replace this second phase to try and address issues we had with the original. Some notes to make:

• Currently the units are arranged in order by default, this part can be re-enabled by un-commenting out the line //shuffleBoxes(); in the document ready function
• The images used for the size boxes (from the rotation/translation interactives) are placeholders, I was planning to keep them but edit out the symbol inside so that the unit was easier to read
• Attempts were made to demonstrate scale with different styles of bar graph, but the units being factors of 1000 meant that usually only one bar was visible at a time (the others being shorter than a pixel)
• Earlier iterations of the PR (notably at commit simplify defining sizes) include real-world examples we were considering using

To finish the interactive a decision needs to be made on what it needs to do and how that should be achieved.