OpenAPI: Add support for query string parameters

[bkoelman]

This PR adds the JSON:API query string parameters (include, filter, sort, page, fields) to OpenAPI schema generation, but in a pretty unstructured way. This is because the parameter names depend on the available relationships and resource types. For example: filter[owner.assignedTodoItems] and fields[people]. It would not only explode the number of combinations (making SwaggerUI pretty unusable and generating many method parameters in the NSwag C# client), but it is not even possible because it leads to potential infinite recursion. For example: ?filter[node.parent.parent.parent...].

So instead the parameters are defined as an unstructured map of key/value pairs. Here's what it looks like in SwaggerUI:

SwaggerUI requires specifying the query string as a JSON object. For example, entering:

{
  "sort": "name",
  "filter": "equals(name,'some')"
}

gets translated by SwaggerUI to:

In the generated C# client, you pass query strings as below:

NodeCollectionResponseDocument response = await apiClient.GetNodeCollectionAsync(new Dictionary<string, string?>
{
    ["sort"] = "name",
    ["filter"] = "equals(name,'some')"
});

If a controller is decorated with [DisableQueryString(JsonApiQueryStringParameters.All)], we could hide the query string from OpenAPI. I didn't implement that, because the information is hard to obtain and it's a corner case. And when users decide to add their own query string parameters, it would incorrectly hide the possibility of providing them.

Closes #1058
Fixes #1374
Fixes #1375
Fixes #1376

QUALITY CHECKLIST

• Changes implemented in code
• Complies with our contributing guidelines
• Adapted tests
• Documentation updated

[codecov]

Codecov Report

Merging #1378 (4a82701) into openapi (6f89ded) will increase coverage by 0.04%.
The diff coverage is 97.26%.

@@             Coverage Diff             @@
##           openapi    #1378      +/-   ##
===========================================
+ Coverage    90.23%   90.27%   +0.04%     
===========================================
  Files          308      308              
  Lines        10114    10159      +45     
  Branches      1692     1693       +1     
===========================================
+ Hits          9126     9171      +45     
  Misses         651      651              
  Partials       337      337              

Files	Coverage Δ
...rc/JsonApiDotNetCore.OpenApi.Client/ApiResponse.cs	100.00% <ø> (ø)
...piDotNetCore.OpenApi/JsonApiOperationIdSelector.cs	84.31% <100.00%> (-0.60%)	⬇️
...rComponents/JsonApiOperationDocumentationFilter.cs	98.17% <100.00%> (+0.26%)	⬆️
...penApi/SwaggerComponents/JsonApiSchemaGenerator.cs	100.00% <100.00%> (ø)
...ggerComponents/ResourceFieldObjectSchemaBuilder.cs	96.80% <100.00%> (+0.02%)	⬆️
...SwaggerComponents/ResourceObjectSchemaGenerator.cs	100.00% <100.00%> (ø)
...onApiDotNetCore.OpenApi/OpenApiSchemaExtensions.cs	81.81% <88.88%> (+31.81%)	⬆️