Add the ability to not include all resources

[bass3l]

Is your feature request related to a problem? Please describe. Not related to a problem, but using swagger-core (and its related deps) that generates the output at runtime, you can specify the following config entry:

<param-name>openApi.configuration.readAllResources</param-name>
<param-value>false</param-value>

Which will result in only including the classes/ops that where annotated by an annotation from io.swagger.v3.oas.annotations namespace.

I'll try to create a pull request for it if considered. I think JaxRSScanner the one that should get the changes?