Local cache for `.nupkg` like other package managers

[o-l-a-v]

Summary of the new feature / enhancement

It could be useful with a local cache of downloaded .nupkg files, like other package managers does.

• Bun: https://bun.com/docs/pm/global-cache
• Chocolatey: https://docs.chocolatey.org/en-us/choco/commands/cache/
• Scoop: https://github.com/ScoopInstaller/Scoop/blob/master/libexec/scoop-cache.ps1

Having this would make it feasible to implement other fatures too, like:

• Verify integrity of already installed resources #1646

Proposed technical implementation details (optional)

• Make it optional.
• Make cache invalidation / deletion / purge logic configurable.
  • Keep to latest version of each script/module?
  • Delete cached items after x days?
• Could help with cache in CI/CD too, like in GitHub actions, if Install-Package did not delete the .nupkg files it downloaded.
• Add some cmdlets to manage cache
  • Get current cached items and total size.
  • Clear cache.