New Pkger feature: export by stack

[jsteenb2]

PR that will drive changes: influxdata/influxdb#18322

The PR above adds the ability to export resources associated with a stack. The current sate of the platform will be output. If a resource has been removed from the platform, but is associated with the stack, it will not be exported. The same goes for associations with labels. If a label association is removed in the platform it will be removed from the pkg that is exported. If a label is added in the platform, it does not get added as it is not associated with the stack.

Relevant URLs

shoudl be added a child command to the influx export command. The new command is:

influx export stack STACKID