improve performance of rh file write

[jedwards4b]

Reorders variables in the rh files. Significantly improves file write performance on derecho.

Fixes #1042

[peverwhee]

looks good. Thanks, @jedwards4b !

[brian-eaton]

@jedwards4b, I'm getting a regression test failure with this mod. Starting from current cam_development (cam6_4_014) merge in this PR and run the izumi/nag test:
ERC_D_Ln9.f10_f10_mg37.QPC6.izumi_nag.cam-outfrq3s_cospsathist
The run fails (I've repeated the failure 3 times) with the following error reported in cesm.log:

Abort with message NetCDF: Start+count exceeds dimension bound in file
/fs/cgd/data0/fischer/ParallelIO/src/clib/pio_darray_int.c at line 998

No traceback is reported.
The outfrq3s_cospsathist test uses several history files with various types of output.

[jedwards4b]

Thanks - I'll try to reproduce.

[jedwards4b]

@brian-eaton I don't think that this is a critical PR - I would suggest that you build the cam tag without it I will debug and update this PR for a future tag.

[brian-eaton]

Thanks Jim. Sounds like a plan.

[jedwards4b]

Did you intend to merge this?

[brian-eaton]

This PR was originally in the miscellaneous fixes PR #1072 which I just merged. When I ran into the test failure and isolated it to this PR I pulled it.