Support for query string parameters

[maurei]

The current OpenApi integration does not support any query parameters. The task is to describe the standard JsonApiDotNetCore query features as query parameters in the OAS:

• filtering
• sorting
• including
• pagination
• field selection

A first effort would be to add all parameters as string key-value pairs. So far two possible directions for a solution have been identified:

• Instantiating a customized ControllerParameterDescriptor and adding it to ActionDescriptor.Parameters, using the metadata mechanism we have built in the core of the OpenApi integration.
• Post-processing using a Swashbuckle IOperationFilter.

[bkoelman]

This should also take [AttrCapabilities] into account.

[bkoelman]

Should take [DisableQueryString] on controllers into account.