support multi-module (#4)

* add multimodule
* re-package modules

server/internal/bitmap/export_test.go

@@ -0,0 +1,9 @@
+package bitmap
+
+import "slices"
+
+func (p Bitmap) value() []uint32 {
+	return slices.Clone(p.bitVector)
+}
+
+var Value = (Bitmap).value