Please add `app.get_new_client()` to help with token rotation

From a discussion in #1324, the only safe way to call the client from outside a bolt handler when token rotation is on is to create a new client each time (as the handlers do)

Since Bolt is currently handling all of this for us, it'd be very useful to have a method along the lines of

client = await bolt.get_new_client(team_id)

that means callers do not need to deal with the InstallationStore and such themselves.

Category (place an x in each of the [ ])

• slack_bolt.App and/or its core components
• slack_bolt.async_app.AsyncApp and/or its core components
• Adapters in slack_bolt.adapter
• Others

Requirements

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Revisa primero la discusión #1324 y, después, inspecciona los puntos de entrada slack_bolt.App y slack_bolt.async_app.AsyncApp y cómo utilizan InstallationStore durante la rotación de tokens. La tarea estará terminada cuando los llamadores puedan obtener un cliente recién creado para un equipo mediante los métodos solicitados sin tener que gestionar el store por su cuenta, tanto en aplicaciones síncronas como asíncronas.