chore: bump @elementar-ui/components to 0.6.20 and update Angular to 20.3.2

- Update schematics and package.json to use @elementar-ui/components version 0.6.20
- Upgrade Angular framework and related dependencies to version 20.3.2 for enhanced features and compatibility
- Adjust `bootstrap` function to support `BootstrapContext` parameter for improved server-side rendering setup
- Update package-lock.json and peer dependencies to align with new versions

Author: pavelsalauyou