Feat: Add export to CSV support

[yuvarajsai]

Feature Enhancement: Export Group Data to CSV

This pull request introduces a new feature that allows users to export group data as a CSV file. The feature enhances accessibility and usability by providing an easily shareable and analyzable data format.

Addressed Issue: Feature request: Export Data as a User-Friendly CSV File (similar to Splitwise) #282

Key Features

• CSV Export Functionality: Users can export group expenses to a CSV file with a single click.
• Comprehensive Data Structure: The exported CSV includes:
  • Date: When the expense occurred.
  • Description: Details of the expense.
  • Category: Expense category.
  • Currency: Currency used.
  • Cost: Total amount of the expense.
  • Is Reimbursement: Whether the expense is a reimbursement or not.
  • Split mode: The method used to split the expense (e.g., Evenly, By shares, By percentage, By amount).
  • Participants: Individuals involved in the expense.

Benefits

• Improved Accessibility: Simplifies access to expense data for non-technical users without requiring JSON parsing.
• Enhanced Data Analysis: Enables users to perform detailed analysis and reporting using spreadsheet tools like Excel or Google Sheets.
• Seamless Sharing: Provides a universally accepted format for easy sharing with group members or other stakeholders.

Implementation Details

• CSV Conversion: The conversion is handled using the @json2csv/plainjs package, ensuring a clean and accurate CSV output.
• Participant Shares Converted to Amounts: For better readability, the participants’ shares are converted into their respective amounts in the CSV file.
• UI Enhancements: To prevent overwhelming the user interface, the "Export to JSON" and "Export to CSV" options are now hidden under a dedicated "Export" button.
• File Naming: The exported CSV file is named using the group name and the date of export, and it is saved with a .csv extension.
• No Changes to Export to JSON: The "Export to JSON" flow remains unchanged and continues to function as expected.

Screenshots:

CSV file opened in Excel:

[yuvarajsai]

@scastiel, can you please review this when you get a chance?