[3.13] AI Gateway: Aliyun provider

[tomek-labuk]

Ticket: https://konghq.atlassian.net/browse/AG-563
Contact: Robin

DoD:

• Update [AI Providers reference page](https://developer.konghq.com/ai-gateway/ai-providers/)

  • Get Aliyun icon from Product Design
  • Add a provider tile for Aliyun
  • Add a provider subsection similar to the Azure section

• Add working Aliyun examples to AI Proxy and AI Proxy Advanced docs

Size: M
Required: Y