fix(xds): print error source and try breaking connection instead of continuing

[XAMPPRocky]

Speculative fix for now, but hopefully we see more insight with these changes.

[quilkin-bot]

Build Succeeded 🥳

Build Id: f11b717b-0f8a-40c5-a7b8-58824d35f084

The following development images have been built, and will exist for the next 30 days:

• us-docker.pkg.dev/quilkin/ci/quilkin:0.10.0-dev-c1bebe3

To build this version:

git fetch [email protected]:googleforgames/quilkin.git pull/1170/head:pr_1170 && git checkout pr_1170
cargo build