feat: clearly indicate which resolver we're using (#885)

See what we documented at https://github.com/ooni/spec/pull/257

Reference issue: https://github.com/ooni/probe/issues/2238

See also the related ooni/spec PR: https://github.com/ooni/spec/pull/257

See also https://github.com/ooni/probe/issues/2237

While there, bump webconnectivity@v0.5 version because this change
has an impact onto the generated data format.

The drop in coverage is unavoidable because we've written some
tests for `measurex` to ensure we deal with DNS resolvers and transport
names correctly depending on the splitting policy we use.

(However, `measurex` is only used for the `tor` experiment and, per
the step-by-step design document, new experiments should use
`measurexlite` instead, so this is hopefully fine(TM).)

While there, fix a broken integration test that does not run in `-short` mode.

internal/measurex/dnsx.go

@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"github.com/ooni/probe-cli/v3/internal/model"
+	"github.com/ooni/probe-cli/v3/internal/tracex"
 )
 
 // WrapDNSXRoundTripper creates a new DNSXRoundTripper that
@@ -42,7 +43,7 @@ func (txp *dnsxRoundTripperDB) RoundTrip(
 	response, err := txp.DNSTransport.RoundTrip(ctx, query)
 	finished := time.Since(txp.begin).Seconds()
 	txp.db.InsertIntoDNSRoundTrip(&DNSRoundTripEvent{
-		Network:  txp.DNSTransport.Network(),
+		Network:  tracex.ResolverNetworkAdaptNames(txp.DNSTransport.Network()),
 		Address:  txp.DNSTransport.Address(),
 		Query:    txp.maybeQueryBytes(query),
 		Started:  started,