Rename url to path for onRequestError request arg (#68672)
### What
* Rename the `request.url` in onRequestError callback arg to
`request.path`
* Align `routeType: "middleware"` with others, only contain the resource
path in the `request.path`, stripped out request origin.
### Why
For non middleware case, the `req.url` in next-server is actual resource
path, which only contains the pathname and search but without request
origin. For middleware case, the origin is included in the `req.url`.
This might be a implementation detail, but for users, having request
origin here might not be critical and super helpful since they will know
the deployment as a global context for error tracking.
Hence we align the property to a variable that not holding request
origin, given a better naming `request.path`. The idea is from `:path`
request header, which represents the resource path, only containing
pathname and search. e.g. `/a/b?c=2`
x-ref:
https://greenbytes.de/tech/webdav/draft-ietf-httpbis-http2-09.html#HttpRequest
Closes NDX-54
