Assume Content-Type is json for endpoints that require json (#4575)

* added default content type filter

* Merge branch 'unstable' of https://github.com/sigp/lighthouse into unstable

* create custom warp json filter that ignores content type header

* cargo fmt and linting

* updated test

* updated test

* merge unstable

* merge conflicts

* workspace=true

* use Bytes instead of Buf

* resolve merge conflict

* resolve merge conflicts

* add extra error message context

* merge conflicts

* lint

common/warp_utils/src/lib.rs

@@ -2,6 +2,7 @@
 //! Lighthouse project. E.g., the `http_api` and `http_metrics` crates.
 
 pub mod cors;
+pub mod json;
 pub mod metrics;
 pub mod query;
 pub mod reject;