memory leak when using vector mapping for Sa_u and Sa_v

[mvertens]

There is a large memory leak when vector mapping used for the stream RYF streams such as
<stream_info name="CORE_RYF8485_JRA.NCEP">
If for this stream - you replace

<    <vectors>Sa_u:Sa_v</vectors>
with
>    <vectors>null</vectors>

There is no longer a memory leak.
So this is definitely a problem in CDEPS.
This vector mapping is also used in CORE2_NYF.NCEP and ERA5_HOURLY
It's interesting that for CORE_IAF_JRA the Sa_u and Sa_v actually come in from different streams

  CORE_IAF_JRA.U_10
  CORE_IAF_JRA.V_10

I am using a CDEPS branch that actually turns on this capability.
fork: https://github.com/mvertens/CDEPS
branch: feature-support_CESM_RYF_mv
You can see the memory leak by simply running the compset
1850_DATM%JRA-RYF8485_SLND_SICE_SOCN_SROF_SGLC_SWAV_SESP