Add dependency-graph-continue-on-failure input param

- Translate to env var for init-script support
- Use when deciding whether to log or rethrow errors
- Add a custom error type to trigger failure in post action

action.yml

@@ -73,6 +73,11 @@ inputs:
     required: false
     default: 'disabled'
 
+  dependency-graph-continue-on-failure:
+    description: When 'false' a failure to generate or submit a dependency graph will fail the Step or Job. When 'true' a warning will be emitted but no failure will result.
+    required: false
+    default: true
+
   artifact-retention-days:
     description: Specifies the number of days to retain any artifacts generated by the action. If not set, the default retention settings for the repository will apply.
     required: false