Use node v20

[alx-khramov]

1. node_modules and yarn.lock were removed and reinstalled via yarn install while using node v20
2. Update advisory engines field in package.json
3. Use .nvmrc for the nvm tool for convenience (a developer can use nvm use command to quickly switch between node versions)
4. Use node 20 for github workflows (checked demo app publishing workflow and it works)

Resolves SI-1189

[changeset-bot]

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