refactor(frontend): remove unused session services

[sebastien-comeau]

Description

Remove unused session services since we switched to Express session #2850

Checklist

• I have tested the changes locally
• I have updated the documentation if necessary
• I have added/updated tests that prove my fix is effective or that my feature works
• I have checked that my code follows the project's coding style by running npm run format:check
• I have checked that my code contains no linting errors by running npm run lint
• I have checked that my code contains no type errors by running npm run typecheck
• I have checked that all unit tests pass by running npm run test:unit -- run
• I have checked that all e2e tests pass by running npm run test:e2e