Remove some subset variables from datasets

[kerfoot]

The following variables should be removed from the ERDDAP dataset subset service:

1. trajectory
2. wmo_id
3. time_uv
4. lat_uv
5. lon_uv
6. u
7. v

Current subset variables example:

ru30-20220906T1523.subset

There is only 1 trajectory and wmo_id for each data sets, so subsetting them based on these variables doesn't make sense. It also doesn't make sense to subset by depth-averaged currents, which is what the remaining variables do.

The list of variables providing subsetting should be:

1. profile_id
2. time
3. latitude
4. longitude

[benjwadams]

Created a PR. Limited subset variables can also be tested on the dev ERDDAP server.

[kerfoot]

merged and closed.

[kerfoot]

Reopening... @benjwadams Existing elements need to have the attribute modified and the catalog needs to be reloaded to remove the bad subset variables.

[benjwadams]

This has to be applied to production -- will do shortly.

[kerfoot]

wmo_id and trajectory added to subset variables. Performance is exceptional. Closing.