Add Path functions (#505)

* Add Path functions

* Add unit tests

pkg/stdlib/path/base.go

@@ -0,0 +1,32 @@
+package path
+
+import (
+	"context"
+	"path"
+
+	"github.com/MontFerret/ferret/pkg/runtime/core"
+	"github.com/MontFerret/ferret/pkg/runtime/values"
+	"github.com/MontFerret/ferret/pkg/runtime/values/types"
+)
+
+// Base returns the last component of the path.
+// or the path itself if it does not contain any directory separators.
+// @params path (String) - The path.
+// @returns (String) - The last component of the path.
+func Base(_ context.Context, args ...core.Value) (core.Value, error) {
+	err := core.ValidateArgs(args, 1, 1)
+
+	if err != nil {
+		return values.EmptyString, err
+	}
+
+	err = core.ValidateType(args[0], types.String)
+
+	if err != nil {
+		return values.None, err
+	}
+
+	pathText := args[0].String()
+
+	return values.NewString(path.Base(pathText)), nil
+}