Resolve "Create scaffolding for testdata"

Description

• Test data files moved to alleles/ella-testdata
• New scripts created for managing use of test data
  • ops/testdata/fetch-testdata.py
  • ops/testdata/reset-fetchdata.py
  • ops/testdata/git.py
• Scope creep
  • fixed review app / local demo functionality
  • devcontainer optimizations
    • database performance: increase shm size, mount docker volume for $PGDATA
    • added several useful extensions

Related issues

Closes #2155 (closed) Relates to #2130 (closed)

Notes to review (code/docs/QA)

Tests

General

• Tests have been added that prove my fix is effective or that my feature works
• Related tests have been modified/removed

Hypothesis testing:

• Soak testing has been done
• Distribution between positive / negative cases has been checked

Database

• Includes changes to database schema
• Includes necessary database migrations

Configuration

• Includes changes to configuration
• Includes configuration migration instructions in documentation