Update devices type of sdwan_attach_feature_device_template

[seconroy]

Description

Do not merge, Requires rework

Convert devices of sdwan_attach_feature_device_template to type set to fix rearrangement issue

Types of Changes

• New feature (non-breaking change which adds functionality)
• Bug fix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to change)
• Build/CI change
• Code quality improvement/refactoring/documentation (no functional changes)

Checklist

• My code follows the code style of this project
• I have added tests to cover my changes
• All new and existing tests pass locally