Define clone/transform template heuristics

Right now we have a few templates that have the purpose of transforming types in various ways. We are however not consistent on their behavior
- recursiveness
- handling of model extends
- naming of the transformed type

For example [Playground](https://cadlplayground.z22.web.core.windows.net/?c=aW1wb3J0ICJAdHlwZXNwZWMvaHR0cCI7DQoNCnVzaW5nIEh0dHDFD21vZGVsIFBhcmVudCB7DQogIGE6IHN0cmluZzsgLy8gV2hlcmUgZGlkIEkgZ28%2FDQp9yjZGb28gZXh0ZW5kc81CYslCzS9UZXPHIS8vIEZsYXR0ZW5lZMdzQ3JlYXRlPEZvbywgIntuYW1lfcYTIj47xzNKdXN0IGRyb3BwxjZiOiBNZXJnZVBhdGNoVXBk0EDKHcVEfQ0K&e=%40typespec%2Fopenapi3&options=%7B%7D)
- `Create` will flatten base models properties
- `MergePatch` will just drop the base model reference without anything(Sounds just like a bug)
- `OmitMetadata/StripMetadata` has the same bug as above (not sure what approach yet we should take hence this issue)

Leaning towards:
- If template is acting recursively it should keep everything
- If template is limited to the type itself then flattening should probably happen `Pick`, `Omit`

Do we need a naming convention for a template that transform recursively vs not. Should recurisve template given an option to apply once