.Net: Added an example to show how to limit token usage with filters - #9451

Motivation and Context

Resolves: #5145

Property OpenAIPromptExecutionSettings.MaxTokens allows specifying maximum number of tokens to generate in one response. In Semantic Kernel, auto function calling may perform multiple requests to AI model, but with the same max tokens value. For example, in case when max tokens = 50, and 3 functions are expected to be called with 3 separate requests to AI model, each request will have max tokens = 50, which in total will result in more tokens used. This example shows how to limit token usage with OpenAIPromptExecutionSettings.MaxTokens property and filter for all requests in the same auto function calling process.

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the SK Contribution Guidelines and the pre-submission formatting script raises no violations
• All unit tests pass, and I have added new tests where possible
• I didn't break anyone 😄