Rework Schema::units into Schema::leafType

Change-Id: I9c1f039e7e054f84559a3d57812d0254db183a99
diff --git a/src/schema.hpp b/src/schema.hpp
index 9a86045..8cdffa1 100644
--- a/src/schema.hpp
+++ b/src/schema.hpp
@@ -55,12 +55,11 @@
     virtual bool listHasKey(const schemaPath_& location, const ModuleNodePair& node, const std::string& key) const = 0;
     virtual bool leafIsKey(const std::string& leafPath) const = 0;
     virtual const std::set<std::string> listKeys(const schemaPath_& location, const ModuleNodePair& node) const = 0;
-    virtual yang::LeafDataType leafType(const schemaPath_& location, const ModuleNodePair& node) const = 0;
-    virtual yang::LeafDataType leafType(const std::string& path) const = 0;
+    virtual yang::TypeInfo leafType(const schemaPath_& location, const ModuleNodePair& node) const = 0;
+    virtual yang::TypeInfo leafType(const std::string& path) const = 0;
     virtual std::optional<std::string> leafTypeName(const std::string& path) const = 0;
     virtual std::string leafrefPath(const std::string& leafrefPath) const = 0;
     virtual std::optional<std::string> description(const std::string& location) const = 0;
-    virtual std::optional<std::string> units(const std::string& location) const = 0;
 
     virtual std::set<std::string> childNodes(const schemaPath_& path, const Recursion recursion) const = 0;
     virtual std::set<std::string> moduleNodes(const module_& module, const Recursion recursion) const = 0;