Refactor LogPage to use MVVM pattern

[ebuzerdrmz44]

Description

Refactor LogPage to use the MVVM pattern by extracting the event log query into a new LogPageViewModel class. The view now delegates data fetching to the ViewModel instead of querying EventLogModel directly.

Related Issue

Part of Phase 5 for #2361

Motivation and Context

Continues the ViewModel migration established in the MiscTab PR. Extracts database queries from the view layer so LogPage focuses purely on UI concerns.

How Has This Been Tested?

Added unit tests in tests/unit/test_log_page_viewmodel.py.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have read the CONTRIBUTING guide.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

I provide my contribution under the terms of the license of this repository and I affirm the Developer Certificate of Origin.