Add Embargo to PCI in Agreement exports

Following implementation of Embargo data in the Agreements local KB, we should include this information in exports. There are three exports to which this is relevant:

1. Agreement export from Agreement->view pane->Actions dropdown->Export
2. Resources in this agreement JSON export from Agreement->view pane->Agreement lines->E-resources covered by this agreement->Export as JSON
3. Resources in this agreement KBART export from Agreement->view pane->Agreement lines->E-resources covered by this agreement->Export as KBART

For 1 and 2 the export should serialise the Embargo statement into package content item. The structure for this is as follows:

"embargo": {
        "movingWallStart": {
          "length": 4,
          "unit": "years"
        },
        "movingWallEnd": {
          "length": 1,
          "unit": "days"
        }
      }

For 3 the embargo statement should be combined into a single string to be put in the embargo_info field in the KBART export. The single string should be created as follows:

• Create a string for movingWallStart by concatenating:
  • "R" + embargo.movingWallStart.length + embargo.movingWallStart.unit converting years->Y, months->M, days->D
• Create a string for movingWallEnd by concatenating:
  • "P" + embargo.movingWallEnd.length + embargo.movingWallEnd.unit converting years->Y, months->M, days->D
• Single embargo statement created by joining the movingWallStart string with the movingWallEnd string using a semicolon to join the two statements if both exist (if only one statement exists, no semicolon should be used.

The above example embargo would result in the following KBART embargo statement:
R4Y;P1D

Attached are files that are:
IMPORT FILE that can be used to create a package in Folio: embargo_examples_kbart_import.tsv
AGREEMENT EXPORT from agreement with package attached: embargo_test_agreement_json_export.json
RESOURCE JSON EXPORT from agreement with package attached: embargo_test_resources_json_export.json
RESOURCE KBART EXPORT from agreement with package attached: embargo_test_resources_kbart_export.tsv