Function validateAndExtractPermit

validateAndExtractPermit(
    extensions: Record<string, unknown>,
    extensionInfo: Eip2612GasSponsorExtensionInfo,
): Eip2612GasSponsorValidationResult & {
    payload?: Eip2612GasSponsorPayload;
}
Validates and extracts the EIP-2612 gas sponsor payload in one step.

This is a convenience function for facilitators that combines extraction and validation against the server's extension info.
Parameters
- extensions: Record<string, unknown>
  The extensions map from a PaymentPayload
- extensionInfo: Eip2612GasSponsorExtensionInfo
  The server's gas sponsor extension info
Returns Eip2612GasSponsorValidationResult & { payload?: Eip2612GasSponsorPayload }
Validation result with the extracted payload if valid
Example
```
const result = validateAndExtractPermit(
  paymentPayload.extensions,
  extensionInfo
);
if (result.valid && result.payload) {
  // Submit permit() on token contract, then settle via Permit2
}
```
- Defined in extensions/src/eip2612-gas-sponsoring/facilitator.ts:96