ActorLogFormatter

Log formatter that prints out the log message nicely formatted, with colored level and stringified extra fields.

It formats the log records so that they:

• start with the level (colorized, and padded to 5 chars so that it is nicely aligned)
• then have the actual log message, if it’s multiline then it’s nicely indented
• then have the stringified extra log fields
• then, if an exception is a part of the log record, prints the formatted exception.