web3: Add Soroban contract upgrade mechanism

[Akatenvictor]

Description

Add Soroban contract upgrade mechanism

Context

This issue is part of the AudioBlocks project improvement initiative. The change should be implemented following the project's existing patterns and conventions.

Acceptance Criteria

• Implementation follows project coding standards
• Changes are tested (unit tests where applicable)
• No regressions introduced
• Documentation updated if needed

[ZacLou]

@ZacLou has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hi, I'd like to work on this issue. I've reviewed the acceptance criteria and the relevant codebase, and I'm confident I can deliver a focused, high-quality PR that meets the requirements.

My plan:

1. Fork the repo and create a feature branch.
2. Implement the requested changes with tests/docs as specified.
3. Open a PR linking back to this Drips issue.

I'm available to iterate quickly on review feedback. Please assign this to me if it looks like a good fit.

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