Logging-json

Added
- Explicit support for python `3.12`. Meaning `taskName` is now considered a reserved keyword where value is supposed to be contained in the record itself (otherwise value will be `taskName` for python < 3.12 when specified).
- New parameters `default_time_format` (default to `%Y-%m-%d %H:%M:%S`) and `default_msec_format` (default to `%s,%03d`) allowing to change the formatting of `asctime`.
- More details can be found in the documentation on what the impact is when changing those values.

Fixed
- non-ASCII but valid UTF-8 values and field names will now be output as provided (they will not be escaped anymore).

Changed
- Default message key is now `message` instead of `msg` to stay in line with python default. If you still want previous behavior, set `message_field_name` to `msg` at formatter creation.

Removed
- Drop support for python 3.6.

Added
- Added `exception_field_name` parameter.

Fixed
- `datetime`, `time` and `date` instances are now represented following [ISO-8601](https://www.iso.org/iso-8601-date-and-time-format.html) format instead of raising a `TypeError`.
- Default to the `str` representation of value instead of raising a `TypeError` for non-standard python types.

Added
- Added `message_field_name` parameter.

Fixed
- Handle `extra` logging parameter.