feat: add starknetkit

[0xEniotna]

Add Starknetkit to scaffold-stark

This PR integrates Starknetkit into scaffold-stark, replacing the custom wallet connector component while maintaining burner wallet functionality.

Types of change

• Feature
• Bug
• Enhancement

Comments

• Replaced custom wallet connection implementation with Starknetkit
• Created a dedicated UI with two separate connection buttons:

1. "Connect Wallet" button that opens the Starknetkit modal with standard wallet options
2. "Burner Wallet" button (only visible in devnet environments) that provides access to dev accounts

• Updated connector configurations to work with both Starknetkit and burner wallet

[metalboyrick]

sorry for the late review, kindly make sure the CI is green first.