Include the ignore installed flag during the update command

When running an update, we should update all modules and dependencies to their highest compatible versions, no matter what is currently installed. The functionality at the moment leaves the possibility of an update not occurring for a dependency if it already has versions satisfied from what is installed pre-update.

We already have the IgnoreInstalled flag that can be used to tell the dependency resolver to ignore any installed versions and treat it as if it were installing from scratch. The work involved here is to set that flag to true by default for the update command.

Start by locating the update command and the existing IgnoreInstalled flag in the package manager. Trace how the flag reaches dependency resolution, then verify that update ignores installed versions and selects the highest compatible versions for all modules and dependencies.

Written by the indexing model from the issue text.