Central package management and lock files

[jmaeagle99]

What was changed

• Centralize package versioning in the Directory.Packages.props file at the repository root.
• Use package lock files to pin package versions and require explicit package version updates.

Why?

Unify the "source of truth" of the package version information.
Allow easier package version updating with fewer source locations.
Better deterministic builds with explicitly known package versions.

Checklist

1. How was this tested: Local and CI Build
2. Any docs updates needed? No