Clean polygon geometries; remove holes, fix right hand rule

[Sujanadh]

What type of PR is this? (check all applicable)

• 🍕 Feature
• 🐛 Bug Fix
• 📝 Documentation
• 🧑‍💻 Refactor
• ✅ Test
• 🤖 Build or CI
• ❓ Other (please specify)

Related Issue

• Issue: OSM Map features are not exactly clipped by AOI #1904

Describe this PR

This PR updates the postgis utils to clean the polygon geojson before any operations such as split by square , split by algorithm, create project outline, generate data extracts. It includes:

• remove_holes: It checks for any holes present in the polygon and removes it using exterior ring
• ensure_right_hand_rule: It ensures each polygon follows right hand rule
• create_single_polygon: It creates a single polygon, mostly a project outline case, while creating projects or generating data extracts. Here, if the geojson has disjoint multipolygons, then it applies a convex hull to create a single AOI, or else it will use an exterior ring to create a single AOI. During data extracts, it won't apply convex hull; we will get data extracts in individual polygons inside MulitPolygon.

With exterior ring for normal multipolygon case:

With disjoint mulitpolygon:

Single AOI for both cases:
Case I: After removing holes, fixing right hand rule and merging all polygons

Case II: Disjoint Multipolygon creating single AOI

Alternative Approaches Considered

Did you attempt any other approaches that are not documented in code?

Review Guide

Notes for the reviewer. How to test this change?

Checklist before requesting a review

• 📖 Read the FMTM Contributing Guide: https://github.com/hotosm/fmtm/blob/main/CONTRIBUTING.md
• 📖 Read the HOT Code of Conduct: https://docs.hotosm.org/code-of-conduct
• 👷‍♀️ Create small PRs. In most cases, this will be possible.
• ✅ Provide tests for your changes.
• 📝 Use descriptive commit messages.
• 📗 Update any related documentation and include any relevant screenshots.

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[spwoodcock]

Nice work, this should help project creation a lot 😁