perftest: support plugin eps for compile_ep_context (#27121)
* Extend compile_ep_context to also support plugin eps
* Adds compile_only option to skip execution, can be used when compiling
for virtual devices
compile_ep_context (physical device)
<img width="1259" height="510" alt="image"
src="https://github.com/user-attachments/assets/14650c17-0c8a-4002-a7ce-e8e4c815a516"
/>
compile_ep_context + compile_only (virtual device)
<img width="1262" height="173" alt="image"
src="https://github.com/user-attachments/assets/2f0844cc-5e83-4b2d-bf0a-0d815d9bad29"
/>