Don't select transitive packages in PM UI when updating a package

[martinrrm]

Bug

Fixes: NuGet/Home#13893

Description

Transitive packages are automatically selected when you are in the Updates tab and clicking the Update button will update the package reference for the top-level packages but also add a package reference in all the projects where the package is used as a transitive dependency, promoting them to top-level, which is not the desired behavior in most of the cases.

Promoting a package from transitive to top-level is not a very common scenario, most likely only done when fixing a vulnerability or resolving a dependency conflict.

PR Checklist

• Meaningful title, helpful description and a linked NuGet/Home issue
• Added tests I'm not adding since it's a UI change in a code path with no tests, I could try to add a unit test if team wants
• Link to an issue or pull request to update docs if this PR changes settings, environment variables, new feature, etc.

[nkolev92]

Can you ask the vendors to add a manual test if you can't add an automated one?