Add workaround for applying Jira default settings to group

What does this MR do?

This MR proposes adding a script that will set all projects within a group (and subgroups) to use the specified group's Jira integration settings.

This currently isn't possible due to limitations in the API (see #337128).

For SaaS customers, they are forced to use the API to set "Custom settings" on all of their projects which is far from ideal. It would be good to have a script documented that has been validated and can be used by Support in these situations. I also imagine such a script will have its uses for self-managed customers as well.

Related issues

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