chore: clean up leftover procedure-related things in core (#6797)

* chore: remove triggering updates

* chore: export isObservable

* chore: move the observable procedure model out of its own directory

core/observable_procedure_map.ts

@@ -0,0 +1,65 @@
+/**
+ * @license
+ * Copyright 2022 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {IProcedureMap} from './interfaces/i_procedure_map.js';
+import type {IProcedureModel} from './interfaces/i_procedure_model.js';
+import {isObservable} from './interfaces/i_observable.js';
+
+
+export class ObservableProcedureMap extends
+    Map<string, IProcedureModel> implements IProcedureMap {
+  /** @internal */
+  constructor() {
+    super();
+  }
+
+  /**
+   * Adds the given procedure model to the procedure map.
+   */
+  override set(id: string, proc: IProcedureModel): this {
+    if (this.get(id) === proc) return this;
+    super.set(id, proc);
+    if (isObservable(proc)) proc.startPublishing();
+    return this;
+  }
+
+  /**
+   * Deletes the ProcedureModel with the given ID from the procedure map (if it
+   * exists).
+   */
+  override delete(id: string): boolean {
+    const proc = this.get(id);
+    const existed = super.delete(id);
+    if (!existed) return existed;
+    if (isObservable(proc)) proc.stopPublishing();
+    return existed;
+  }
+
+  /**
+   * Removes all ProcedureModels from the procedure map.
+   */
+  override clear() {
+    if (!this.size) return;
+    for (const id of this.keys()) {
+      this.delete(id);
+    }
+  }
+
+  /**
+   * Adds the given ProcedureModel to the map of procedure models, so that
+   * blocks can find it.
+   */
+  add(proc: IProcedureModel): this {
+    return this.set(proc.getId(), proc);
+  }
+
+  /**
+   * Returns all of the procedures stored in this map.
+   */
+  getProcedures(): IProcedureModel[] {
+    return [...this.values()];
+  }
+}