Reorder languages in Configure Source Formatter UI

ClangSupport::name() returns "clang" rather than "C" or "C++". So the languages KDevelop supports best are never found in active or loaded languages. As a result, the items of the Language combobox are always sorted alphabetically. When kdev-python plugin is installed, "Python" appears at the top of the combobox list, while "Python 3" is placed at the bottom, because Python::LanguageSupport::name() returns "Python". The resulting Language list order is therefore unsatisfactory: unsupported "C#" is above best-supported "C++"; "Python" is always at the top; "Python 3" is very far from "Python" and can be easily missed.

It is possible to fix this issue by analyzing MIME types supported by active and loaded language plugins. But runtime language order changes can confuse the user and make understanding this configuration UI even more difficult (see BUG 358798). Stable and predictable language list order makes more sense to me. So this commit drops the dependency on ILanguageController and ILanguageSupport, keeps the alphabetical order, but moves unsupported "C#" and "Java" to the bottom of the list.

Before: After: