Add throwTranslatedWriteException, refactoring, async helper

[katcharov]

Refactoring for JAVA-5379

Introduces throwTranslatedWriteException (in CSOT will allow replacing isExpired with onExpired).

This also introduces a helper, and the second commit, which can be reviewed independently, is a simple refactoring (move, increase visibility).

[vbabanin]

Looks good overall! Just a couple of questions and suggestions.