workflowmgr and Temporal: remaining tasks

Major:

• Add Life Cycle Management (LCM) hooks: registering and launching workflows during app LCM.
  • See issue 89 for background. Enhance EMCO to do these:
    • Register workflows that need to be executed at these LCM points:
      • before or after a Deployment Intent Group (DIG) is instantiated, terminated, upgraded or migrated.
      • before or after a cluster is registered or deleted.
      • before or after a logical cloud is instantiated, terminated, etc.
    • Monitor status of said workflows, in all the ways supported in Phase 1.
  • Cancel/terminate any of said workflows.
• Security considerations.

More:

• Apply JSON schemas. Note that the timeout values should be accepted as in temporal-migrate-workflow issue 1. The workflowmgr need only pass these values to the workflow client and need not parse/use the timeout values itself. Only the workflow client and the worker need to parse/apply the timeout values.
• Add unit tests.
• Create gitlab CI for migrate workflow repo.
• TODOs in source: cd src/workflowmgr/; git grep TODO. Some examples:
  • Apply timeouts/retry policies for query and cancel APIs, if there is interest.
  • Provide a more human-readable output for status query, if there is interest.
  • Allow query parameters.