MySQL & user information.

[NozoMizore7]

1. change DB from Sqlite3 to MySQL.
2. add MySQL DB-init file(DDLs).
3. add page and function of user information.
4. add scripts of common run and debug command.

Checklist:

• Add tests that demonstrate the correct behavior of the change. Tests should fail without the change.
• Add or update relevant docs, in the docs folder and in code.
• Add an entry in CHANGES.rst summarizing the change and linking to the issue.
• Add .. versionchanged:: entries in any relevant code docs.
• Run pre-commit hooks and fix any issues.
• Run pytest and tox, no tests failed.