Doc legacy database migration/data synchronization job.

[doug-lovett]

Issue #: /bcgov/entity#33734

Description of changes:
Semi-automate this task as a GCP cloud run like job. Needs to run locally for now as running a BCGOV VPN client is required to access the legacy database.
The job description is:
Synchronize legacy document records in the Oracle globalp db correspondence schema with the DRS.
Legacy database access requires running a VPN.
Synchronization is in one direction: from legacy to DRS.
Synchronization is in 2 steps:
1. New document records created since the last time this job ran.
2. Updates to document records that exist in the DRS and where changes have occurred since the last time
this job ran (scanning a document).

Detail:
    Execute a summary query to get the most recent DRS scanned doc timestamp and legacy document record key for
    each DRS document class.
    For each document class:
    1. Fetch new records from the legacy database. For each record:
        a. If there is a legacy document, save it to cloud storage.
        b. Insert into the tracking table staging_legacy_documents with the cloud storage path if available.
        c. Insert into the DRS documents table.
        d. Insert into the DRS document_scanning table if the legacy record includes scanning information.
    2. Fetch updated records from the legacy database that have documents.
        a. Save the legacy document to cloud storage.
        b. Update into the tracking table staging_legacy_documents with the cloud storage path and other data.
        c. Update the DRS documents table.
        d. Insert into the DRS document_scanning table if the legacy record includes scanning information.

    Optionally save csv formatted summary/status information for the job by document class.