Allow the actor / author to optionally be retained when importing rules

Description

Currently, we override the authorAccountId value of rules when they are imported using “Rules Import”. We do this as the authorAccountId could be different across different accounts (DC vs Cloud). Instead, we default the id to the authorAccountId from whichever user uploaded the rule.

We have had a case where the user knows that the id exists, and is correct, and wishes to instead persist this ID, not the user uploading the rules.

Steps to reproduce

1. Export a rule as JSON

1. Set the authorAccountId value in the JSON to anything you like or leave it be

1. Using the rule import tool, re-upload the rule

1. Note that the author field of the rule is not honoured, and is instead set as you (the user uploading the rule)