OOIION-1552 Fix handling of recursion parameter in the platform agent's FSM handler

So the recursion parameter is properly captured in the platform agent's FSM handlers.

Includes specific test exercising recursion=False with a small platform hierarchy: ion/services/sa/observatory/test/test_platform_launch.py:TestPlatformLaunch.test_hierarchy_recursion_false

Fixes specific jira: https://jira.oceanobservatories.org/tasks/browse/OOIION-1552

@MauriceManning please review/merge.