Add style for reply popup. Fix ALL of the linting issues

resources/styles/nheko-dark.qss

resources/styles/nheko.qss

src/ChatPage.h

src/TextInputWidget.cpp

src/TextInputWidget.h

src/popups/PopupItem.cpp

src/popups/ReplyPopup.cpp

src/popups/ReplyPopup.h

src/popups/SuggestionsPopup.cpp

src/popups/SuggestionsPopup.h

src/timeline/TimelineView.h

src/timeline/TimelineViewManager.cpp