[marif-nexthop]

Pre-submission checklist

• I've ran the linters locally and fixed lint errors related to the files I modified in this PR. You can install the linters by running pip install -r requirements-dev.txt && pre-commit install
• pre-commit run

Summary

PR commit stack:

1. [Nexthop][m4340nhp] Add the platform_manager config #1871
2. This (top of stack)

Add the m4340nhp BSP platform mapping, which buildFromXcvrLib builds from the platform's platform_manager.json, and use it in qsfp_service, led_service and wedge_qsfp_util, as for m4061nhp. BspPlatformMapTest gets an m4340nhp case.

Test Plan

On a m4340nhp device, qsfp_service and led_service start and fboss2 show transceiver lists all 66 transceivers. The changed targets build in the OSS build.