Feature request: Add support for manipulating operations generation via IOperationFilter

**Describe the issue**
It would be nice to allow to implement custom logic to manipulate the generation of operations and schemas, similarly to what Swashbuckle provides: [Extend Generator with Operation, Schema & Document Filters](https://github.com/domaindrivendev/Swashbuckle.AspNetCore#extend-generator-with-operation-schema--document-filters)

**Example use cases**
* Adjust the operation definition based on method attributes via IOperationFilter
* Add or update response definitions via IOperationFilter
* Ignore custom method parameter in function methods (IOperationFilter)

This feature is a successor of feature request #376 after the support of IDocumentFilter where implemented.

Start by reviewing the existing IDocumentFilter support and feature request #376, then compare the requested IOperationFilter behavior with Swashbuckle's operation, schema, and document filters. Define support for manipulating generated operations and schemas, including the listed use cases, and verify that the resulting OpenAPI output reflects those changes.

Written by the indexing model from the issue text.