Bugfix/sdk misc (#2847)

* misc sdk fixes

* version bump

* formatting

* add missing dependency to root

* alpha.16 and beta.17

* beta.18

sdk/package/lib/util/Drop.ts

@@ -0,0 +1,26 @@
+export abstract class Drop {
+  private static weak: { [id: number]: Drop } = {}
+  private static registry = new FinalizationRegistry((id: number) => {
+    Drop.weak[id].drop()
+  })
+  private static idCtr: number = 0
+  private id: number
+  private ref: { id: number } | WeakRef<{ id: number }>
+  protected constructor() {
+    this.id = Drop.idCtr++
+    this.ref = { id: this.id }
+    Drop.weak[this.id] = this.weak()
+    Drop.registry.register(this, this.id, this)
+  }
+  protected weak(): this {
+    const weak = Object.assign(Object.create(Object.getPrototypeOf(this)), this)
+    weak.ref = new WeakRef(this.ref)
+    return weak
+  }
+  abstract onDrop(): void
+  drop(): void {
+    this.onDrop()
+    Drop.registry.unregister(this)
+    delete Drop.weak[this.id]
+  }
+}