Database error when abbreviations multi-byte characters

[arteymix]

MySQL storage limit for text is based on the number of bytes, not the number of characters.

We historically addressed this issue by abbreviating certain strings. This is not enough however, because this operation operates on characters, not bytes.

This problem has started arising in the single-cell branch due to the lengthy subset names that result from pseudo-bulking. I've added a bunch of string utilities to complement Commons Lang that truncate and abbreviate based on the resulting byte representation.

The fix should be back-ported on the next patch release.