refactor(ngcc): abstract task selection behind an interface (#32427)

This change does not alter the current behavior, but makes it easier to
introduce `TaskQueue`s implementing different task selection algorithms,
for example to support executing multiple tasks in parallel (while
respecting interdependencies between them).

Inspired by/Based on @alxhub's prototype: alxhub/angular@cb631bdb1

PR Close #32427

packages/compiler-cli/ngcc/src/execution/utils.ts

@@ -32,3 +32,7 @@ export const onTaskCompleted =
             pkgJsonUpdater, entryPoint.packageJson, packageJsonPath, propsToMarkAsProcessed);
       }
     };
+
+/** Stringify a task for debugging purposes. */
+export const stringifyTask = (task: Task): string =>
+    `{entryPoint: ${task.entryPoint.name}, formatProperty: ${task.formatProperty}, processDts: ${task.processDts}}`;