zipped reports download

[gnmahanth]

Fixes #

Changes proposed in this pull request:

• Download report as account/node wise pdf in zip #2322
• zipped_report is the newly added bool field, this controls if the pdf/xlsx report needs to be zip file containing all the individual node/accounts

sample request:

curl 'https://<console-ip>/deepfence/reports'  \
-H 'authorization: Bearer <token>'   \
--data-raw '{
  "filters": {
    "advanced_report_filters": {},
    "include_dead_nodes": true,
    "node_type": "host",
    "scan_type": "compliance",
    "severity_or_check_type": []
  },
  "report_type": "pdf",
  "zipped_report": true
}'   --insecure