WIP: simplify DefineMiddleware, Middleware

[devkral]

Checklist

• The code has 100% test coverage.
• The documentation was properly created or updated (if applicable) following the correct guidelines and appropriate language.
• I branched out from the latest main or is a sub-branch.

Summary or description

This idea makes DefineMiddleware more compatible to other asgi frameworks.
By not using app as keyword but as positional argument we can use DefineMiddleware as decorator.

However it will probably break a lot, so just see it as a suggestion.

[codspeed]

Merging this PR will not alter performance

✅ 21 untouched benchmarks

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_{Comparing devkral/idea/more_flexible_middleware (295eb7b) with main (0261563)}

[devkral]

do you like the idea? Shall I pursue it? We might need to update ravyn too.