add spc_perplot to the getLocTOS() funtion

[srweintraub]

Is your feature request related to a problem? Please describe.
The NRCS initial characterization pits (DP1.10047.001) have offset information that is needed to calculate their precise location, similar to many other TOS sampling efforts, yet the spc_perplot table is not included in the getLocTOS() function.

Describe the solution you'd like
Add spc_perplot to the list of tables that can be run with gotLocTOS.

Describe alternatives you've considered
Manual calculations can work after using getLocByName() and following the instructions in the DPUG, it would just be nice to provide this for users that want it.

Additional context
Christine is going to a meeting and asked me how to calculate precisie locations for the pits, this is how we learned you can't do it with getLocTOS. So there's at least one use case, though I admit I haven't been asked for this by others.

[srweintraub]

@cklunch this is a low-priority enhancement request, but perhaps a nice to have for when you have time.

[cklunch]

@srweintraub Thanks for letting me know! I thought we had captured all the TOS products that needed it, thanks for the catch.