Evaluate pros and cons of using specific device names vs. generic size names as labels for Responsive Preview

Spin-off from #1741498-132: Add a responsive preview bar to Drupal core → . There, Dries requested that continued discussion about this topic be spun off into a new issue, so this is it.

The latest patch in that issue uses specific device names as the labels for the preset sizes that can be previewed:
- iPhone 5
- iPhone 4
- iPad
- Nexus 4
- Nexus 7
- Typical desktop

In #1741498-39: Add a responsive preview bar to Drupal core → , Damien proposed:
- Small phone
- Phone
- Phablet
- Tablet
- Desktop

In #1741498-130: Add a responsive preview bar to Drupal core → , yoroy proposed:
- S
- M
- L
- XL

In #1741498-132: Add a responsive preview bar to Drupal core → , Dries said:

Having talked to various users about this at numerous occasions, I feel pretty strong about using device names

But Bojhan responded with:

Could you provide more background on how you presented the case, and what feedback you got... I like that you are performing user research, but its a little vague on the particulars - which is important for us to understand how users perceive this.

Note that the list is stored as a configuration file, so can be customized per site through a configuration UI, per distribution, by other modules in code, etc. The discussion here is about what we want core defaults to be.

TODO: Update this issue summary with other considerations that should be considered besides user preference as revealed through user research.