[IO-1607][internal] Hotfix for Yolov8

[owencjones]

Problem

YoloV8 was misidentifying items as complex polygons and refusing to export them.

Solution

Improved identification logic, and added test case and tolerated old scenario in case it's needed for anything.

Changelog

Refactor to YoloV8 exporter
Test added

[linear]

IO-1607 BUG: Yolo v8 export generated in incorrect format (json instead of .txt and .labels) + slightly unclear definition of simple vs complex polygons

BUG submission from: Patryk Gronostajski
Summary (describe an issue):
Yolo v8 export generated in incorrect format (json instead of .txt and .labels) + slightly unclear definition of simple vs complex polygons

Michal and Owen seem to have already figured out the first part, however, the simple vs complex polygon issue still needs to be investigated. Currently, polygons aren't exported even if they are simple polygons. More information in the slack thread linked below. I'll attach an example of the same export in yolov8, darwin json v2 and a SS of the polygons.
Share Loom/Screenshots with Console/Network opened:
https://vseven.slack.com/archives/CJUN8TRJA/p1692614116139219
Darwin affected version
V2
Environment (production/staging; browser and OS version)
2.0 prod
Impact
All (all Darwin users are impacted)
Priority
🔴 SWAT Urgent - an urgent problem that blocks users
Steps to reproduce

1. create simply polygon
2. export in yolo v8 format
   Expected Behaviour
   all simple polygons and bounding boxes are exported in the expected yolo format
   Team & Dataset Link
   staging
   Intercom ticket

Customer Name

Renewal timeline

ARR

Tier

Assigned CSM

[michalwski]

LGTM

[Nathanjp91]

is complex_polygon/circle/other annotation types not applicable to YOLO?

[owencjones]

Largely speaking, Yolo has historically been bounding boxes, and now supports polygons too, but ellipses, points, and other types are not supported - with many (2D plane) types, we could still process the bounding box and include it, but this wasn't in scope of the feature, and it was decided to include only bbox and simple polys for now.