* made api.Scaling.Max a pointer, so we can detect (and complain) when it is neglected
* added checks to HCL parsing that it is present
* when Scaling.Max is absent/invalid, don't return extraneous error messages during validation
* tweak to multiregion handling to ensure that the count is valid on the interpolated regional jobs
resolves#8355
- tg.Count defaults to tg.Scaling.Min if present (falls back on previous default of 1 if Scaling is absent)
- Validate() enforces tg.Scaling.Min <= tg.Count <= tg.Scaling.Max
modification in ApiScalingPolicyToStructs, api.TaskGroup.Validate so that defaults are handled for TaskGroup.Count and
