Refactor codebase to async/await – `spo sitedesign task list` until `spo storageentity remove`

-	`spo sitedesign task list`
-	`spo sitedesign task remove`
-	`spo sitescript add`
-	`spo sitescript get`
-	`spo sitescript list`
-	`spo sitescript remove`
-	`spo sitescript set`
-	`spo storageentity get`
-	`spo storageentity list`
-	`spo storageentity remove`
