[feature/performance] sqlite pragma optimize on close (#2596)

* wrap database drivers in order to handle error processing, hooks, etc

* remove dead code

* add code comment, remove unused blank imports

internal/db/bundb/basic.go

@@ -27,7 +27,7 @@ import (
 )
 
 type basicDB struct {
-	db *DB
+	db *bun.DB
 }
 
 func (b *basicDB) Put(ctx context.Context, i interface{}) error {