Replace issue triage workflow with issue templates

[spwoodcock]

The AI-assisted triage bot

• I would like to propose we remove the issue-triage workflow currently in place.
• It relies on external calls to OpenAI to do text summarisation (I think this is kindly paid by Piero currently, but eventually ODM would need to pay?).
• I think this makes sense based on the AI-assistance stance set in the contribution guide: https://github.com/OpenDroneMap/documents/blob/master/CONTRIBUTING.md#use-of-ai
• A few relevant issues were closed accidentally, but I think have been re-opened if necessary 👍

Issue templates

• Github supports issue templates, that prompt the user to do the right thing on submission (either visit the forums, provide test data / logs, etc).
• There is already an issue template but it's in the docs.
• I added a commit to take this issue template and make a bug report & feature request template.