[Azure Search] Consider boosting direct dependencies over transitive dependencies

[karann-msft]

3.x+ clients don't send info if a download is a direct or transitive install. As a result, we don't have an accurate count of direct installs which ends up boosting package ranking.

Target queries:

• aspnet
• aspnetcore
• cef
• discord
• sharpdx
• metalama

@joelverhagen provided some additional context, caveats, and workarounds for the metalama case here: #9485 (comment).

[joelverhagen]

Some thoughts:

Dependencies come and go from version to version. We should consider looking at all versions of a package to determine all of the direct dependencies it has ever had. Then, we can map that to a list of dependencies per package ID, weighted by the relative number of downloads per version.

The specific case we care most about is core packages depended on by a top level "productized" package. For example, xunit is top level and xunit.core is core. Microsoft.AspNetCore.Mvc is top level and Microsoft.AspNetCore.Mvc.Core is core. These cases have the same owner. We should consider only doing the download count subtraction for packages that have the same owners (or perhaps share a common owner).

Dependencies vary from TFM to TFM. We can consider weighting the dependency by TFM frequency perhaps as defined by client telemetry on project restore TFM.

[loic-sharma]

Another customer report: #8782 (comment)

Searching with the keyword "maui" comes up with primarily transitive dependencies.

Target query: maui