use .fromisoformat() for sqlite datetime, date, time parsing

use .fromisoformat() for sqlite datetime, date, time parsing

SQLite datetime, date, and time datatypes now use Python standard lib
``fromisoformat()`` methods in order to parse incoming datetime, date, and
time string values. This improves performance vs. the previous regular
expression-based approach, and also automatically accommodates for datetime
and time formats that contain either a six-digit "microseconds" format or a
three-digit "milliseconds" format.

Fixes: #7029
Change-Id: I67aab4fe5ee3055e5996050cf4564981413cc221