Simplify debts + group balances

[krokosik]

Closes #158 Closes #58

• added personal balances on group page underneath the total balance
• added a balance list page for group
• added a simplify debts toggle in group options and a database field
• implemented a debt simplification algorithm based on this article
• created some unit tests and added Jest
• moved the expense list into a component shared with both the firend and group page
• added new shadcn aliases for compatibility with newer CLI versions
• moved some devDependencies from prod dependencies in package.json
• fixed some missing keys console errors due to incorrect usage of React fragments
• fixed a dev console error on missing Web Push key throwing an undefined query result error