server-esm: Solve a few straightforward imports

src/services/sync_mutex.ts

@@ -3,7 +3,7 @@
  * (like consistency checks) can use this mutex to make sure sync isn't currently running.
  */
 
-const Mutex = require('async-mutex').Mutex;
+import { Mutex } from "async-mutex";
 const instance = new Mutex();
 
 async function doExclusively<T>(func: () => T) {

src/share/shaca/entities/sattribute.ts

@@ -1,10 +1,9 @@
 "use strict";
 
+import AbstractShacaEntity from "./abstract_shaca_entity";
 import { SAttributeRow } from "./rows";
 import SNote from "./snote.js";
 
-const AbstractShacaEntity = require('./abstract_shaca_entity');
-
 class SAttribute extends AbstractShacaEntity {
 
     attributeId: string;

src/share/shaca/entities/snote.ts

@@ -27,7 +27,7 @@ class SNote extends AbstractShacaEntity {
     parentBranches: SBranch[];
     parents: SNote[];
     children: SNote[];
-    private ownedAttributes: SAttribute[];
+    ownedAttributes: SAttribute[];
     private __attributeCache: SAttribute[] | null;
     private __inheritableAttributeCache: SAttribute[] | null;
     targetRelations: SAttribute[];

src/share/shaca/shaca-interface.ts

@@ -8,7 +8,7 @@ export default class Shaca {
     notes!: Record<string, SNote>;
     branches!: Record<string, SBranch>;
     childParentToBranch!: Record<string, SBranch>;
-    private attributes!: Record<string, SAttribute>;
+    attributes!: Record<string, SAttribute>;
     attachments!: Record<string, SAttachment>;
     aliasToNote!: Record<string, SNote>;
     shareRootNote!: SNote | null;