Bump lodash and @sap/approuter in /app

Bumps [lodash](https://github.com/lodash/lodash) to 4.18.1 and updates ancestor dependency @sap/approuter. These dependencies need to be updated together.


Updates `lodash` from 4.17.23 to 4.18.1
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](lodash/lodash@4.17.23...4.18.1)

Updates `@sap/approuter` from 21.2.1 to 21.3.0

---
updated-dependencies:
- dependency-name: lodash
  dependency-version: 4.18.1
  dependency-type: indirect
- dependency-name: "@sap/approuter"
  dependency-version: 21.3.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]