Tracking issue • Post-axum migration improvements

[leovalais]

Tracking issues for problems in the axum migration PR #8047.

We decided to solve these problems afterwards in other PRs as #8047 is large and conflicts with everyone. It also blocks #8171.

• Design a replacement for the routes! macro
• Naming and homogeneity pass (good first issue)
• Implementing our own otel middleware to stop using axum-tracing-opentelemetry and check the need for TraceLayer
• evaluating axum_typed_multipart and test liveries import (good first issue)
• Disable /search dry parameter in non-debug builds & harmonize endpoint results #8673
• Rename document_key to document_id in /document APIs (good first issue)
• editoast: improve naming of extracted variables in several handlers #8674