Set proper descriptions for tools

Task-number: QTBUG-61970
Change-Id: I188638ac433f3f313a1e93b5f26f73f8fc680ed6
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Andy Shaw <andy.shaw@qt.io>

src/tools/idc/idc.pro

@@ -2,4 +2,5 @@ option(host_build)
 CONFIG += force_bootstrap
 SOURCES = main.cpp
 
+QMAKE_TARGET_DESCRIPTION = "Active Qt Interface Description Compiler"
 load(qt_tool)

tools/dumpcpp/dumpcpp.pro

@@ -3,4 +3,5 @@ DEFINES += QT_NO_CAST_TO_ASCII QT_ASCII_CAST_WARNINGS
 
 SOURCES = main.cpp
 
+QMAKE_TARGET_DESCRIPTION = "Active Qt DumpCpp"
 load(qt_tool)

tools/dumpdoc/dumpdoc.pro

@@ -2,4 +2,5 @@ QT += axcontainer widgets
 
 SOURCES += main.cpp
 
+QMAKE_TARGET_DESCRIPTION = "Active Qt DumpDoc"
 load(qt_tool)