Fix the wrong check of running thread

[wptestyyh]

Type

• Bug fix
• Feature addition
• Feature update
• Documentation
• Build Infrastructure

Side Effects

• Breaking change
• Non-functional change

Goals

std::thread::joinable() is not the same as running. The thread can be joinable but already finished. The second call will be failed always if we use joinable to check if the thread is running.

Technical Details

• Create flag m_timedEnableRunning and m_timedDisableRunning to check if the thread has finished
• Add new test Succeeds when a timed enable operation is finished and Succeeds when a timed disable operation is finished

Test Results

• /netremote-test-unit "WifiAccessPointTimedEnable API"
  ===============================================================================
  All tests passed (38 assertions in 1 test case)
  ./netremote-test-unit "WifiAccessPointTimedDisable API"
  ===============================================================================
  All tests passed (40 assertions in 1 test case)

Reviewer Focus

None

Future Work

Publish the fix in 0.5.3

Checklist

• Build target all compiles cleanly.
• clang-format and clang-tidy deltas produced no new output.
• Newly added functions include doxygen-style comment block.