Add createSep24Deposit flow function

[MissBlue00]

Task

Add a createSep24Deposit function to implement SEP-24 deposit flow for on-ramping.

Details

• Function signature: createSep24Deposit(params: DepositParams): Promise<DepositResponse>
• Implement Stellar Ecosystem Proposal 24 deposit flow
• Handle interactive web anchor URL generation
• Track deposit status through completion
• Add DepositParams and DepositResponse interfaces
• Integration point: anchor-service package

Test

Run pnpm --filter @stellar-pay/anchor-service build to verify no TypeScript errors.

[Joeloo1]

@Joeloo1 has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

I’d like to work on this issue. Please assign it to me. Thanks!

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Joeloo1 to this issue.