Support --dtd-exposed-uri in dt tool

[DanTup]

--dtd-exposed-uri is a flag supported by the DevTools server but not in dt serve. This makes it difficult to run DevTools from source in a web based IDE because Dart-Code will pass this flag and the call to dt serve will fail.

[DanTup]

@kenzieschmoll I'm confused by the DCM failure - have you seen this before? It's all code I haven't changed, but it doesn't look like any other PRs or tests on head have failed in this way.

packages/devtools_app/test/screens/deep_link_validation/deep_links_screen_test.dart (1 issue):
WARNING   This ignore does not suppress any diagnostic. Consider removing it.
          at packages/devtools_app/test/screens/deep_link_validation/deep_links_screen_test.dart:39:14
          avoid-unused-ignores : https://dcm.dev/docs/rules/


packages/devtools_app/test/screens/deep_link_validation/select_project_view_test.dart (1 issue):
WARNING   This ignore does not suppress any diagnostic. Consider removing it.
          at packages/devtools_app/test/screens/deep_link_validation/select_project_view_test.dart:22:14
          avoid-unused-ignores : https://dcm.dev/docs/rules/


packages/devtools_app/test/standalone_ui/vs_code/devtools_test.dart (1 issue):
WARNING   This ignore does not suppress any diagnostic. Consider removing it.
          at packages/devtools_app/test/standalone_ui/vs_code/devtools_test.dart:33:14
          avoid-unused-ignores : https://dcm.dev/docs/rules/

[kenzieschmoll]

Those failures are odd considering there aren't any ignores in those files CC @incendial

I opened #9310 to upgrade to DCM 1.30.0. We'll see if checks pass there.

[incendial]

It's all code I haven't changed, but it doesn't look like any other PRs or tests on head have failed in this way.

This is really odd, but it seems that other PR with 1.30.0 shows correct failures.

[DanTup]

Yeah, there's one ignore warning but that line does have an ignore. Odd. I'll try rebasing this one after that lands so it re-runs on the new version.