Reset navigation IsModified flags and clear on UoW

[maliming]

Resolve #24806

[Copilot]

Pull request overview

This PR adjusts EF Core navigation-change tracking lifecycle in AbpDbContext to better support auditing/navigation change detection across a Unit of Work, aiming to resolve #24806 where role changes can yield missing NewValue in audit logs.

Changes:

• Replace removal of modified navigation-tracking entries with a “reset modified flags” approach (ResetChangedFlags).
• Defer clearing of AbpEfCoreNavigationHelper state until Unit of Work completion (or immediately when no UoW exists).

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

File	Description
framework/src/Volo.Abp.EntityFrameworkCore/Volo/Abp/EntityFrameworkCore/ChangeTrackers/AbpEfCoreNavigationHelper.cs	Renames the cleanup API and changes behavior from removing modified entries to resetting modification flags.
framework/src/Volo.Abp.EntityFrameworkCore/Volo/Abp/EntityFrameworkCore/AbpDbContext.cs	Updates SaveChangesAsync cleanup to reset flags after save and clear helper state on UoW completion.