Sqlite: Improve Sqlite wrapper

It is now possible to read values at once.

for (auto [name, value] : statement.tupleValues<String, int>(1000, "foo", 20))
   ....

Change-Id: I3d4bc5218810b4620e1df625126aa490f30bbc71
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/libs/sqlite/sqliteglobal.h

@@ -37,6 +37,8 @@
 #  define SQLITE_EXPORT Q_DECL_IMPORT
 #endif
 
+namespace Sqlite {
+
 enum class ColumnType : char
 {
     Numeric,
@@ -46,10 +48,11 @@ enum class ColumnType : char
     None
 };
 
-enum class IsPrimaryKey : char
+enum class Contraint : char
 {
-    No,
-    Yes
+    NoConstraint,
+    PrimaryKey,
+    Unique
 };
 
 enum class ColumnConstraint : char
@@ -84,3 +87,5 @@ enum TextEncoding : char
 #endif
 
 };
+
+} // namespace Sqlite