Support trajectory profile DSG data type

[noaaroland]

I have enhanced LAS 9 to include products to make a trajectory plot and a profile plot from a trajectoryprofile data sets. When these products are selected they produce the symbol scripts in the attached zip, but the current products that run to make each of those types of plots fail with errors since the DSG type is not as expected.

We need to either modify the script sequence that gets invoked or create new ones for these two types of products.

Completing this sequence of steps will give us very basic support for this data type where in we can create a trajectory plot (which would if we use the default PyFerret behavior, show the average value of the profile between the selected depths) and a ZT profile ribbon plot of the selected profiles.

Here are the steps for this to be included in an LAS release:

1. Release PyFerret 7.6.3 (or higher) with native support for trajectory profiles. Already done if you don't include the -c conda-forge on the conda update pyferret nothing happens to pyferret. Should be conda update -c conda-forge pyferret.
   2.Using the symbol set tjp_trajectory.jnl (see attached tjp.zip) (and any additional inputs needed) create a trajectory plot (probably using PLOT/ALONG=xy) This runs to completion but the plot doesn't show much because the range is too small.
2. Using the symbol set tjp_profile.jnl (see attached tjp.zip) create a ribbon plot in ZT showing the profiles in the selected XYZT region. This appears to work just fine.

tjp.zip

The Trajectory plot:

The profile plot:

[noaaroland]

Here's the current state:

It runs on whatever the default pyferret build is on dunkel:

[rhs@dunkel scripts]$ pyferret
        NOAA/PMEL TMAP
        PyFerret v7.63 (optimized)
        Linux 2.6.32-754.33.1.el6.x86_64 - 09/28/20
         8-Dec-20 10:57

yes? use c16ba57ca446dda89c513174a7a2c0db_netcdf.nc
yes? define variable allgood = temperature[z=@ngd]
yes? define symbol ngood_data = `allgood[e=@sum]`
 !-> define symbol ngood_data = 8
yes?

However that same command fails on the build that currently ships with conda:

(pyferret) schweitzer@GREEN:/mnt/c/Users/schweitzer/Documents/tjp$ pyferret
        NOAA/PMEL TMAP
        PyFerret v7.63 (optimized)
        Linux 4.15.0-1096-azure - 10/13/20
         8-Dec-20 11:00

yes? use c16ba57ca446dda89c513174a7a2c0db_netcdf.nc
yes? define variable allgood = temperature[z=@ngd]
yes? define symbol ngood_data = `allgood[e=@sum]`
 **ERROR: invalid command: grave accent doesnt evaluate to scalar
          allgood[e=@sum]
yes?