Add instance resource allocation example

[Roxanacmaria]

Summary

This PR adds a new Unikraft Cloud example for Instance Resource Allocation.

The example documents how to configure memory and virtual CPU allocation for instances running on Unikraft Cloud, both through the kraft CLI and through the Unikraft Cloud Platform API.

Current contents

• README for the new instance-resource-allocation example
• create files (Dockerfile, Kraftfile,server.py,test_resources.py, ukc.config.template)
• validate and refine the example implementation
• functional testing on Unikraft Cloud
• final cleanup and review

Scope of the example

The example is intended to cover:

• configuring instance memory with -M / --memory
• configuring virtual CPUs with -V / --vcpus
• deploying an instance with custom resource allocation
• retrieving instance information to verify the configured resources
• using equivalent API-based operations

Status

Draft / work in progress.