Installation package handling - specify proper standard for Windows install packages

At the moment .msi or any other install packages are handled through

`chocolatey\infrastructure.app\services\RegistryService.cs / get_installer_keys` function which basically scans through all registry keys `SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall` after installation.

Some of registry structure is designed indeed from installation perspective, like you have a lot of useful data like
`DisplayName`, `InstallLocation` - but not suited for choco requirements - choco misses such information as Package id, and version as well.

From Microsoft documentation perspective - see https://docs.microsoft.com/en-us/windows/win32/msi/uninstall-registry-key
all versions uses only 3 digits, not 4.

But Microsoft never disallowed to extend their registry format.

You can create whatever keys / values in registry.

I would propose to create chocolatey official standard on registry keys.

`PackageId` would specify string tag for package id.
`PackageVersion` would specify chocolatey package version. (Which will be full 4 digits)

Using this kind of approach would obsolete the need of `chocolateyuninstall.ps1` power shell script, and would also allow choco to operate purely on registry, without need to have local chocolatey installations.