Support loguru-style message matching

[etianen]

Originally intended as be part of #28, this has been moved to a separate issue following discussion with loguru devs in Delgan/loguru#1072. 👍

Proposed API

Support .format()-style placeholders like this:

from logot.contrib.loguru import logged

logot.wait_for(logged.info("Hello {}"))

Support matching structured data like this (requires #25):

logot.wait_for(
    logged.bind(foo="bar").info("Hello {}")
)

Implementation

Parsing of the format-style placeholders should be nice and easy using string.Formatter.parse(). Probably easier than the normal %-style placeholder parsing!

[etianen]

Matching the style of every 3rd-party log integration is going to get tedious. Let's not.