* WIP export OpenAPI definitions from service examples
* allow services to optionally define an OpenApi Paths Object instead of examples
* make use of param descriptions and required query params
* convert other 'core' services to declare openApi..
..instead of examples
* tweak descriptions for standard query params
* move stuff around, add a high-level integration test for category2openapi
* update simple-icons text refs #9054
* remove legacy param names