feat: can rebind the monaco editor command handler

[kittaakos]

What it does

It binds the monaco editor command handler to self so that a downstream project can customize it. Currently, it is not possible:

Error: Could not unbind serviceIdentifier: MonacoEditorCommandHandlers
    at __webpack_modules__.../node_modules/inversify/lib/container/container.js.Container.unbind (container.ts:170:19)
    at __webpack_modules__.../node_modules/inversify/lib/container/container.js.Container.rebind (container.ts:161:14)
    at container.ts:310:41
    at ContainerModule.registry (arduino-ide-frontend-module.ts:1052:3)
    at __webpack_modules__.../node_modules/inversify/lib/container/container.js.Container.load (container.ts:110:27)
    at index.js:113:1

How to test

Theia works, and basic editor commands such as find, select all, undo, and redo functional.

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

[vince-fugnitto]

LGTM 👍

[JonasHelming]

@kittaakos Do you want to merge?

[msujew]

@JonasHelming Akos cannot merge, as he isn't a team member. @vince-fugnitto Needs to do that.