KF-33 add tests for TimerThread

[Kellesi]

Task: https://jira.dev.local/jira/browse/KF-33

[Copilot]

Pull Request Overview

This PR adds comprehensive unit tests for the TimerThread class to improve test coverage. The tests verify timer callback execution, proper timing behavior, and cleanup when the timer is stopped or goes out of scope.

• Added TimerThreadTest.cpp with scenario-based tests for callback execution and timer lifecycle
• Updated CMakeLists.txt to include the new test file in the build

Reviewed Changes

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

File	Description
test/TimerThreadTest.cpp	New test file implementing comprehensive tests for TimerThread functionality including callback execution, join behavior, and scope-based cleanup
test/CMakeLists.txt	Added TimerThreadTest.cpp to the test driver build configuration

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