wip: Make cross-module visibility explicit via Visibles structs

All access is/will be through interfaces accessed through these structs.

This introduces several distinct storage units:
+ DB for server state
+ DB for codeql databases
+ query pack store

The steps for manually creating needed databases are in the README

pkg/storage/storage.go

@@ -28,6 +28,10 @@ func NewStorageSingle(startingID int) *StorageSingle {
 	return &s
 }
 
+func (s *StorageSingle) Setup(v *ServerStorageVisibles) {
+	s.modules = v
+}
+
 func (s *StorageSingle) NextID() int {
 	s.currentID += 1
 	return s.currentID