Add icetea newportmode (#585)

Summary:
Description
Add new profile PROFILE_800G_4_PAM4_RS544X2N_COPPER = 57 to switch_config.thrift. and front port three new port speed mode
<img width="105" height="188" alt="image" src="https://github.com/user-attachments/assets/f38616bb-a2bb-4b43-bd1e-ceeca723bd2c" />

Motivation
Add new profile id, and support front port new requirment

Pull Request resolved: #585

Test Plan:
• Build "fboss-platform-mapping-gen" target in FBOSS build container.
• To test with platfrom_name="icetea800bc", and all required csv files in the ./platform/icetea800bc.
• compile sai test/wedge image and run on icetea unit with agent config

<img width="2429" height="160" alt="image" src="https://github.com/user-attachments/assets/99abb025-5a09-4dbd-8038-67166ac11715" />

<img width="1070" height="82" alt="image" src="https://github.com/user-attachments/assets/c9b64be1-e10b-4ae7-b01f-16b414e752b6" />
<img width="701" height="941" alt="image" src="https://github.com/user-attachments/assets/0371b5f8-56ac-475b-a457-6aca65b6e9a7" />

Reviewed By: harshitgulati18

Differential Revision: D84707216

Pulled By: shiva-menta

fbshipit-source-id: 396dc6640614131b7d070ac1cd71ef2bb09f8b14

Author: cel-gl

fboss/agent/Platform.cpp

@@ -263,6 +263,7 @@ int Platform::getLaneCount(cfg::PortProfileID profile) const {
     case cfg::PortProfileID::PROFILE_400G_4_PAM4_RS544X2N_OPTICAL:
     case cfg::PortProfileID::PROFILE_400G_4_PAM4_RS544X2N_COPPER:
     case cfg::PortProfileID::PROFILE_800G_4_PAM4_RS544X2N_OPTICAL:
+    case cfg::PortProfileID::PROFILE_800G_4_PAM4_RS544X2N_COPPER:
       return 4;
 
     case cfg::PortProfileID::PROFILE_400G_8_PAM4_RS544X2N: