Minimal permissions for 'spo serviceprincipal related' commands

We're adding a new Permissions section to all commands. This section will document the minimal delegated and application permissions required to execute the command.

The goal is to:

• Make it easier to run the CLI with custom app registrations and application permissions.
• Ensure we only document the minimal set of permissions needed.
• Keep documentation consistent by placing the Permissions section right before the Examples section.
• If there are multiple resources, order them alphabetically
• If there are commands that only support one type of auth (like delegated or app-only), we have an example for that as well. E.g. m365 planner tenant settings list - Permissions

Resources

• Writing the docs page
• How to document minimal permissions
• Planner example 1
• Planner example 2

Commands in scope

This issue covers the following commands:

• m365 spo serviceprincipal grant add
• m365 spo serviceprincipal grant list
• m365 spo serviceprincipal grant revoke
• m365 spo serviceprincipal permissionrequest approve
• m365 spo serviceprincipal permissionrequest deny
• m365 spo serviceprincipal permissionrequest list
• m365 spo serviceprincipal set

Read the linked guidance on writing docs and documenting minimal permissions, then inspect the documentation for the seven listed spo serviceprincipal commands. Add a Permissions section immediately before Examples for each command, documenting the minimal delegated and application permissions and ordering multiple resources alphabetically. Done means all commands in scope follow the stated format, including auth-type-specific cases.