By misusing Config, this netplay-related code opened up a race condition between Config::OnConfigChanged() and SerialInterface::SerialInterfaceManager::UpdateDevices() that could cause iterator invalidation.
Expanded the use of the lock mutex already used for loading the player's existing unlock status to guard against races involving the Achievements dialog window reading from data AchievementManager might be in the process of updating. The lock has been exposed publicly and the AchievementsWindow uses it in its UpdateData method, and anywhere else that might modify data used to render that window has also been wrapped with it.
AchievementManager now has a SetUpdateCallback method for providing a single universal callback for anytime something important changes in the achievement state, such as logging in/out, game load/close, or events such as achievement unlocks. AchievementsWindow sets this callback in its own init to its UpdateData method so that the AchievementsWindow gets updated when one of these changes takes place.
This widget is a tab in the AchievementsWindow that displays the player's current achievement progress: which achievements are locked or unlocked, and the progress of achievements that have progress metrics.
This widget displays a header on the AchievementsWindow dialog above the tabs that shows the currently logged in user (if there is one) and the game they are playing (if there is one).
Added some small methods to AchievementManager to expose useful data for displaying in an achievement UI. Also moved a couple things from private to public for the same purpose.
1 ) When first opened, the (user selected) post process shader config widget would print the wrong values on the text label next to int range sliders. For example if the range was from 1 to 6, and the value loaded from the config was 1, the label would print 0 when first opened, to then start showing the correct value once the slider was first moved.
This mirrors the behaviour of the float slider code below:
```auto* const value_box = new QLineEdit(QString::asprintf("%f", m_config_option->m_float_values[i]));```
2 ) The defautl int slider value would also be set wrong on first load, as it was being divided by the slider max instead of the slider step amount (again, just like for the float implementation). This is a mistake I had made with my previous submission.
Fixing all the places it's used turned out to be a more complicated task than anticipated. So let's remove this for now so we don't confuse users with cryptic error messages...
