Show `patched` flag in dependency docs

Many of our (bazel) dependencies have local patches applied

The dependency docs show the commit/version/etc that is compiled into Envoy - but does not indicate whether the dep/source has been patched - probably it would be good to show this

https://www.envoyproxy.io/docs/envoy/latest/intro/arch_overview/security/external_deps.html#external-dependencies

not sure how easy it would be to collate the info as the deps are patched independently of the info in `repository_locations` but i guess we could shift that info to there