Got EVLA CMS restores working via casa_envoy, using casa_restorepipescript.py when it exists

Restores have been manually tested both with a PPR in the arguments (but no piperestorescript in the cal tar) and without one (with a piperestorescript in the cal tar). No other use-cases of casa_envoy have been manually tested.

To test restores with piperestorescript:

1. Copy the following from /lustre/aoc/cluster/pipeline/dsoc-dev/workspaces/skagan_testing/test_data/with_piperestorescript_2 into your own testing directory:
   1. rawdata/
   2. metadata.json
2. Add empty products and working directories
3. Remove rawdata/products
4. Call /lustre/aoc/cluster/pipeline/dsoc-dev/workspaces/skagan_testing/skagan-casa_envoy3 --restore metadata.json

Without piperestorescript (differences bolded):

1. Copy the following from /lustre/aoc/cluster/pipeline/dsoc-dev/workspaces/skagan_testing/test_data/sans_piperestorescript_with_ppr_in_args into your own testing directory:
   1. rawdata/
   2. metadata.json
   3. PPR.xml
2. Add empty products and working directories
3. Remove rawdata/products
4. Call /lustre/aoc/cluster/pipeline/dsoc-dev/workspaces/skagan_testing/skagan-casa_envoy3 --restore metadata.json PPR.xml