feat(customizations): add support for operational preferences when creating stacksets

[allcloud-sahar-hagbi]

Hi,
Following our meeting (AWS LZA's team & AllCloud), here is one of the feature requests we discussed there.
The feature request is to control the operational preferences option when deploying stacksets in customization-config.yaml.
Right now, there is no option to control that option, and default values are supplied:

operationPreferences: { failureTolerancePercentage: 25, maxConcurrentPercentage: 35, regionConcurrencyType: 'PARALLEL', }

I exported the operational preferences property to be controlled by the user as an input along with the other properties that are not mentioned above:
failureToleranceCount, maxConcurrentCount, regionOrder

Those are all the options for the operational preferences property.
It is important to say that I left the default values as it was before, which won't have any affect on any users using the solution.

[allcloud-sahar-hagbi]

hi @erwaxler,
Can we prioritize the release of this feature in the upcoming version 1.10.0?
This is a very simple yet crucial feature for the migration path in our customer's environment.
Thx in advance.