Add command to switch "autobuild" on/off

Hi,

most of the time I run maven build outside of vscode in the terminal. This interferes with the extension's way of detecting changes. It seems that the extension also starts building, which leads to alot of ClassNotFoundExceptions in the maven build (probably because vscode deleted the already build classes while the maven build was running).

To circumvent this I used to temporarily disable the auto build feature back when I was using Eclipse.
I know this is also possible via the settings menu.

Environment

• Operating System: macOS 11.5.1 (20G80)
• JDK version: openjdk version "15" 2020-09-15
• Visual Studio Code version: 1.60.0-insider
• Java extension version: v0.18.2

Steps To Reproduce

1. Start a long running maven build (something simple will not work)
2. See ClassNotFoundExceptions in the maven build

Expected Result

• Add the `Autobuild: Enabled/Disabled" settings to the command pallet
• Add the `Autobuild: Enabled/Disabled" to the status bar, at least to show the status, better even to allow to toggle the setting.

This would allow to easily switch between those two modes.

El issue señala la configuración de autobuild existente y su implementación en settings-menu; empieza por localizar esa configuración y los registros de comandos y de la barra de estado de la extensión. Verifica la reproducción de larga duración de Maven y, después, confirma que la configuración se puede alternar desde la Command Palette y la barra de estado, y que su estado habilitado o deshabilitado es visible.