Upgrade @mendix/pluggable-widgets-tools to v10.21.1

[vadymv-mendix]

Important changes

• Switch from Yarn to Pnpm to address issues with packages hoisting, idle build process, duplicate packages installed
• Upgrade Rollup 2 -> 3, remove all internal packages overrides and rely only on widget-tools repo as the source of truth
• Upgrade/remove unnecessarily declared dependencies, align versions of prettier, eslint, rollup, jest across the entire codebase
• Fix Jest and Rollup compatibility issues
• Remove @testing-library/react dependency - it was used only by piw-utils-internal package which seem to work fine with the react-native testing library instead
• Upgrade @testing-library/react-native

To continue working locally after switching to Pnpm

• Remove node_modules and run pnpm install - should be that simple.
• Check the PNPM_MIGRATION.md document for main changes

Potential issues

• Github pipeline scripts rely a lot on filtering out projects for build/testing and this mechanism differs a lot compared to yarn so something might not work as expected (see https://pnpm.io/filtering)