Fix xlsform question ordering + pmtile generation when custom TMS

[spwoodcock]

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

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

Related Issue

Fixes #1697

Describe this PR

• Also fixes PMTile generation when using custom TMS provider, which didn't work always previously.
• Now we use the oam provider for osm_fieldwork.basemapper.

Review Guide

• Generate pmtiles + mbtiles with various providers.
• A custom TMS should be tested for both pmtiles + mbtiles too.

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.

[optional] What gif best describes this PR or how it makes you feel?