Limit request bodies size (default 250MB)

[peb-adr]

No description provided.

[peb-adr]

This also includes a version update of caddy.
2.3.0 ->2.7

As a nice side effect of this, it seems the odd

docker-proxy-1  | {"level":"error","ts":1693489378.8311799,"logger":"http.handlers.reverse_proxy","msg":"aborting with incomplete response","error":"context canceled"}

logs no longer occur \o/

[peb-adr]

As proposed in OpenSlides/openslides-client#2732 (comment), 8859538 sends the limit with response.

I called the header Request-Body-Max-Size. There may be better suited names, however I could not find a standard one for this use case. Content-Length came to mind but does not seem appropriate, as the body of the request is empty.

[peb-adr]

I will prepend the custom header with 'X-' to make it clear as such.

[peb-adr]

This is a bit annoying.
Until caddy 2.7.0 (where caddyserver/caddy#5652 is fixed) using the request_body caddy directive will return status 502 (instead of 413), which is not good since the client cannot easily differentiate.
However caddy 2.6.0 was a major update which also introduced a problem for us where connections from the autoupdate service are closed correctly. So in order to get to the needed version, that has to be investigated first...