[WiX 5] Migrate workloads

[joeloff]

Description

Migrate workload tasks from WiX v3 to v5.

• Generate SDK style projects for workload installers. Additional task parameters are provided to deal with CPM when adding package references.
• Replace HEAT usage with new <Files/> element. HEAT will be deprecated in WiX v7.

Test Updates

• Add tests for workload pack groups.
• Expand MSI tests
  • Validate install record and dependency provider keys
  • Validate specific files and directories based on the type of installer (manifest, pack, pack group, or workload set)