Desktop: Performance: reduces the overhead of using MenuBar's API

[ken1kob]

This PR is one of PRs resolving issue #6386. It reduces the overhead of using the following MenuBar's APIs.

• Changing enabled, checked and visible properties of MenuItem
• Menu.setApplicationMenu()

Problem

The view (A) in the following Performance Analyzer image shows note switching between notebooks. In this view, re-rendering MenuBar takes a fair part of the total time. Especially, there are four MenuBar's scheduleUpdate() calles for re-rendering. They are heavy, and their total time is 245 msec.

Cause

As illustrated below, Electron's MenuBar is in a different process from the React's rendering process. So, using MenuBar's API from React codes involves ipc and has a very large overhead. Besides, since MenuBar is out of React's efficient rendering system, it should be carefully updated.

Since scheduleUpdate() has many MenuBar's API calls, it involves many ipc calls and so it's heavy.

In addition, each re-rendering of MenuBar, its native counter part in Electron is always reconstructed. It also costs high.

Treatment

This PR provides two treatments.

Treatment 1

To make scheduleUpdate() lighter, this PR provides convenience functions that enable changing multiple MenuItems' properties at once. The functions are implemented in app-desktop/gui/util/MenuBarUtils.ts.

Treatment 2

Currently, MenuBar always reconstructs itself when re-rendered. It's redundant. This PR makes MenuBar being reconstructed only when its content is changed.

Result

The view (B) of the above Performance Analyzer images shows the execution time of MenuBar's scheduleUpdate() becomes so reduced that it cannot visually observed.

[ken1kob]

This commit was replaced to be mergeable with v2.9.17.

[laurent22]

See https://github.com/laurent22/joplin/pull/6446#issuecomment-1817817260