fix(@angular/build): assert that asset input paths are within workspace root

Ensure that asset patterns defined as objects with an 'input' property are validated to be within the workspace root.

- In '@angular/build', introduce a shared 'isSubDirectory' utility and apply it to both 'normalizeAssetPatterns' and 'resolveAssets'.
- In '@angular-devkit/build-angular', apply similar validation during 'normalizeAssetPatterns'.
- Add and update integration and E2E tests to prevent regressions from absolute and relative path traversal attempts.