feat: support submenus on editor/title

[erha19]

Types

• 🎉 New Features
• 🐛 Bug Fixes

Background or solution

fixed #2067.

在编辑器顶部 ... 菜单支持插件 submenus 注册及展示，效果如下：

Web：

Electron:

Changelog

support submenus on editor/title

[codecov]

Codecov Report

Base: 57.75% // Head: 57.75% // Increases project coverage by +0.00% 🎉

Coverage data is based on head (dbc6f4a) compared to base (80d6723).
Patch coverage: 40.00% of modified lines in pull request are covered.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2088   +/-   ##
=======================================
  Coverage   57.75%   57.75%           
=======================================
  Files        1291     1291           
  Lines       81101    81098    -3     
  Branches    16925    16924    -1     
=======================================
+ Hits        46839    46840    +1     
+ Misses      31144    31141    -3     
+ Partials     3118     3117    -1     

Flag	Coverage Δ
jsdom	52.55% <40.00%> (+<0.01%)	⬆️
node	16.91% <40.00%> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...ages/core-browser/src/bootstrap/inner-providers.ts	100.00% <ø> (ø)
packages/editor/src/browser/types.ts	100.00% <ø> (ø)
...s/extension/src/browser/vscode/contributes/menu.ts	51.77% <ø> (ø)
packages/editor/src/browser/menu/editor.menu.ts	31.81% <40.00%> (+3.81%)	⬆️
packages/monaco/src/browser/schema-registry.ts	71.11% <0.00%> (+2.22%)	⬆️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.

[Ricbet]

LGTM