Some minor UI fixes (#7044)

* fix ladspa browser description (unwanted line breaks), add missing labels to instruments' controls

* some more ui fixes

* translation context + style fixup

src/gui/editors/AutomationEditor.cpp

@@ -1429,8 +1429,8 @@ void AutomationEditor::paintEvent(QPaintEvent * pe )
 		p.drawText( VALUES_WIDTH + 20, TOP_MARGIN + 40,
 				width() - VALUES_WIDTH - 20 - SCROLLBAR_SIZE,
 				grid_height - 40, Qt::TextWordWrap,
-				tr( "Please open an automation clip with "
-					"the context menu of a control!" ) );
+				tr( "Please open an automation clip by "
+					"double-clicking on it!" ) );
 	}
 
 	// TODO: Get this out of paint event