Handle JsonExceptions in RequestDelegateFactory

[halter73]

This change causes minimal API route handlers to respond with a "400 Bad Request" instead of "500 Internal Server Error" when given a request body with an application/json Content-Type but malformed JSON.

Before, we expected this to throw an InvalidDataException but malformed JSON results in a JsonException instead.

I plan to backport this to release/6.0-rc2.

Fixes #36499

[Tratcher]

InvalidDataException is what's thrown by the form parser. Was this accidentally copied from that code path?

[rafikiassumani-msft]

@halter73 are you returning 400 to be consistent with MVC? Any reason why we are not returning 422 ?

[halter73]

@halter73 are you returning 400 to be consistent with MVC? Any reason why we are not returning 422 ?

I mostly did this to be consistent with MVC and our current InvalidDataException behavior.

Also, the rfc claims

The 422 (Unprocessable Entity) status code means the server
understands the content type of the request entity (hence a
415(Unsupported Media Type) status code is inappropriate), and the
syntax of the request entity is correct (thus a 400 (Bad Request)
status code is inappropriate) but was unable to process the contained
instructions. For example, this error condition may occur if an XML
request body contains well-formed (i.e., syntactically correct), but
semantically erroneous, XML instructions.

And I think JsonExceptions indicate the JSON is not "well-formed". A 422 would be more appropriate if the request was missing a required property or something like that (assuming that was something we supported).

[halter73]

/backport to release/6.0-rc2

[github-actions]

Started backporting to release/6.0-rc2: https://github.com/dotnet/aspnetcore/actions/runs/1243143334

[github-actions]

@halter73 backporting to release/6.0-rc2 failed, the patch most likely resulted in conflicts:

$ git am --3way --ignore-whitespace --keep-non-patch changes.patch

Applying: Handle JsonExceptions like InvalidDataExceptions in RequestDelegateFactory
Using index info to reconstruct a base tree...
M	src/Http/Http.Extensions/src/RequestDelegateFactory.cs
M	src/Http/Http.Extensions/test/RequestDelegateFactoryTests.cs
Falling back to patching base and 3-way merge...
Auto-merging src/Http/Http.Extensions/test/RequestDelegateFactoryTests.cs
Auto-merging src/Http/Http.Extensions/src/RequestDelegateFactory.cs
Applying: Don't catch InvalidDataExceptions when reading JSON
Using index info to reconstruct a base tree...
M	src/Http/Http.Extensions/src/RequestDelegateFactory.cs
M	src/Http/Http.Extensions/test/RequestDelegateFactoryTests.cs
Falling back to patching base and 3-way merge...
Auto-merging src/Http/Http.Extensions/test/RequestDelegateFactoryTests.cs
CONFLICT (content): Merge conflict in src/Http/Http.Extensions/test/RequestDelegateFactoryTests.cs
Auto-merging src/Http/Http.Extensions/src/RequestDelegateFactory.cs
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0002 Don't catch InvalidDataExceptions when reading JSON
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".
Error: The process '/usr/bin/git' failed with exit code 128

Please backport manually!

[halter73]

@captainsafia Can you approve this PR too? Thanks!