pldmd: Parse JSON PDRs

[spargaon]

Since the remote terminus does not support DMTF DSP0248 command GetPDR, use a file with manully mapped PDRs at the remote terminus in JSON format.
Once read and parsed, PDRs are acted upon to create numeric sensors according to their respective numeric sensor PDR.

[spargaon]

This is working code. Created a SP7 branch for review but the exact same code would work for SP8 and will
create a SP8 branch for review shortly as well.

[spargaon]

jsonpdrs.txt

[ojayanth]

:Keep AMD-specific logic in oem/amd, use JSON configs for PDRs, and hook generators during platform init—just like IBM and Ampere do. This ensures clean, maintainable, and upstream-compliant design. you can refer Refer to pldm/docs/pdr_implementation.md to follow genrator pattern

[spargaon]

:Keep AMD-specific logic in oem/amd, use JSON configs for PDRs, and hook generators during platform init—just like IBM and Ampere do. This ensures clean, maintainable, and upstream-compliant design. you can refer Refer to pldm/docs/pdr_implementation.md to follow genrator pattern

Thanks @ojayanth , will work on the changes.

[spargaon]

Also, I think we need this https://gerrit.openbmc.org/c/openbmc/pldm/+/85434 which is still being reviewed.
Current pldm code (pldmd) in OpenBMC does not support Numeric Effecters PDRs for both Numeric and Compact Sensor PDRs, the change above ushers that in.

The .json file has only one of the multiple compact numeric sensors that exist on the remote terminus (PMFW), so all those sensors need to be coded in as well in the .json file.