Support dev_server rule

[geaden]

dev_server rule was supported in

https://github.com/dart-archive/rules_dart/blob/78a4e1ba257bbe9a9d7a064c8cde8c5317059e17/examples/web_app/BUILD#L40-L46

Any plans on supporting it here?

[cbracken]

We'd need to give some thought as to how we'd want to support it, but no objections to supporting it here!

One goal with this repo was to remove a lot of the complexity we accumulated in the old rules trying to interoperate with a ton of internal Google legacy infra, so right now things are relatively lightweight.

To get live edit-rebuild behaviour, we'd need the equivalent of the internal iblaze tool, which hadn't been open-sourced at the time, but looks like it's available in the bazel-watcher repo now. There was a fair bit of complexity in the rules dealing with iblaze. The DDC build, on the other hand, is relatively straighforward I think. The old rules have a lot of naughty behaviour around path manipulation, but I suspect it wouldn't be a huge effort to port them.

Thanks for filing the issue!