Resolve "Justifier.py integration with VAT"

Closes #170 (closed)

This MR updates the justifier.py script to use the VAT to retrieve the CVE information needed to generate the justification spreadsheet. All expected functionality is implemented and tested, but there are still some comments that need to be added and likely a few items that need to be cleaned up.

Relevant Jobs:

https://repo1.dso.mil/dsop/redhat/ubi/ubi8-minimal/-/jobs/1231241

https://repo1.dso.mil/dsop/redhat/ubi/ubi8/-/jobs/1231227

https://repo1.dso.mil/dsop/ironbank-pipelines/pipeline-runner/-/jobs/1231283

https://repo1.dso.mil/dsop/google/distroless/static/-/jobs/1263743

Relevant spreadsheets generated using VAT:

pipeline-runner_0.1-113829-justifications__1_.xlsx

ubi8-minimal_8.3-113826-justifications.xlsx

ubi8_8.3-113825-justifications.xlsx

static_nonroot-115942-justifications.xlsx