Restructure api

Introduces a new API structure:

• /api/get/all/gt
• /api/get/all/workflows
• /api/get/all/runs
• /api/get/latest/runs
• /api/post/run
• /api/post/gt
• /api/post/workflow

Documentation is available at https://quiver-dev.sub.uni-goettingen.de/docs.