Start moving toward a single authoritative class for all settings. This

is necessary to get rid of technical debt before we drastically increase
the complexity of settings by adding per model settings and mirostat and
other fun things. Right now the settings are divided between QML and C++
and some convenience methods to deal with settings sync and so on that are
in other singletons. This change consolidates all the logic for settings
into a single class with a single API for both C++ and QML.

gpt4all-chat/main.cpp

@@ -21,7 +21,6 @@ int main(int argc, char *argv[])
     QCoreApplication::setOrganizationDomain("gpt4all.io");
     QCoreApplication::setApplicationName("GPT4All");
     QCoreApplication::setApplicationVersion(APP_VERSION);
-    QSettings::setDefaultFormat(QSettings::IniFormat);
 
     Logger::globalInstance();