feat: Add World Bank API wrapper

[rudrasheth]

feat: Add World Bank API wrapper

## Description

This pull request introduces a new, comprehensive API wrapper for the World Bank Open Data API. This adds a crucial worldwide macroeconomic and development data source to the Fincept Terminal, moving beyond specific assets like stocks and crypto.

The wrapper is built following the project's established standards, with a full command-line interface for easy integration and testing.

## Key Features

• Global Data Coverage: Fetches data for over 200 countries and regions.
• Indicator Fetching: Implements core functionality to retrieve specific economic time-series data (e.g., GDP, population, inflation) using indicator codes.
• Commodity Prices: Includes a function to fetch global commodity prices (the "Pink Sheet") for assets like crude oil and coffee.
• Advanced Filtering: Supports filtering by single countries, multiple countries, and specific date ranges.
• Utility Endpoints: Includes functions to list all available countries and data sources for discovery.

## API Information

• Provider: World Bank Open Data
• Free Tier: Yes, the API is public and does not require a key.
• Documentation: [https://datahelpdesk.worldbank.org/knowledgebase/topics/125589-apis](https://www.google.com/search?q=https://datahelpdesk.worldbank.org/knowledgebase/topics/125589-apis)

## Testing

The following commands have been manually tested and confirmed to be working correctly:

• countries: Fetched the full list of countries.
• indicators IN NY.GDP.PCAP.CD: Successfully retrieved GDP per capita for India.
• commodity_prices PCRUDE_BRENT: Successfully retrieved historical price data for Brent crude oil.
• economic_snapshot DE: Fetched a correct economic summary for Germany.
• Error handling for invalid commands and timeouts was also verified.