how to specify serialization format for model type path/query parameters ?

[qiaozha]

In OpenAPI3, it has specify that both path/query parameters/headers can be primitive types, arrays and objects. https://swagger.io/docs/specification/describing-parameters

But I am not sure how to serialize the object path/query parameter as the collectionFormat is not enough for us.

For example, objects can be serialized as:

form – /points?color=R,100,G,200,B,150 or /points?R=100&G=200&B=150, depending on the explode keyword, 
deepObject – /points?color[R]=100&color[G]=200&color[B]=150

Also, there's label and matrix style of path parameter for object and more serialization details can be found here, not sure how to specify those.

See original customer issue from Azure/autorest.typescript#2033

Items to take into account:

• Ability to add a prefix to the param name if serialized as individual entires(explode) [Feature request] Support purview query parameters Azure/typespec-azure#21
• Ability to serialize as a media type(json, xml, etc.)