Add Schema::leaftype(const std::string&)

Will be used in the CLI.

Change-Id: I31ddc63e92bfad4c37b5b2b65ae72c33e939af2f
diff --git a/src/schema.hpp b/src/schema.hpp
index e4636cf..ef90542 100644
--- a/src/schema.hpp
+++ b/src/schema.hpp
@@ -75,6 +75,7 @@
     virtual bool listHasKey(const schemaPath_& location, const ModuleNodePair& node, const std::string& key) const = 0;
     virtual const std::set<std::string> listKeys(const schemaPath_& location, const ModuleNodePair& node) const = 0;
     virtual yang::LeafDataTypes leafType(const schemaPath_& location, const ModuleNodePair& node) const = 0;
+    virtual yang::LeafDataTypes leafType(const std::string& path) const = 0;
     virtual yang::LeafDataTypes leafrefBase(const schemaPath_& location, const ModuleNodePair& node) 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;