issue for scattered refactor related PR

## Enhancement
issue for scattered refactor related PR, those refactors might **NOT** focus on some specific functions, so use this issue for them, such as
- make some literal a const
- make group of literals a enum
- moving structs or files to a better position
- renaming structs or files to a better name

No file, test, or entry point is named, and the issue groups several unrelated refactor types. Start by selecting one concrete refactor and locating the affected Go package and its existing tests. Done should mean the selected literals, enums, structs, or files are reorganized or renamed without changing behavior, with the relevant tests passing.

Written by the indexing model from the issue text.