BB2-2818 Update batch create users and apps command

[sharonfruit]

JIRA Ticket:
BB2-2818

User Story or Bug Summary:
This change adds options on an existing Django command that will allow
developers to specify how many dev users, synthetic bene users, and applications
in their local environment to be able to test with. If no options are specified on the
call, then the defaults are what the old hard coded values were.

What Does This PR Do?

• Adds command options to create_test_users_and_applications_batch
• Updates the README with this new information, removes broken link
• Adds directory with .rif files needed for the command to generate users/apps

What Should Reviewers Watch For?

If you're reviewing this PR, please check these things, in particular:

• Broken link was removed in README and subsequent ticket will include the information about
  BFD synthetic data.

What Security Implications Does This PR Have?

Submitters should complete the following questionnaire:

• If the answer to any of the questions below is Yes, then here's a link to the associated Security Impact Assessment (SIA), security checklist, or other similar document in Confluence: N/A.
  • Does this PR add any new software dependencies? No.
  • Does this PR modify or invalidate any of our security controls? No.
  • Does this PR store or transmit data that was not stored or transmitted before? No.
• If the answer to any of the questions below is Yes, then please add StewGoin as a reviewer, and note that this PR should not be merged unless/until he also approves it.
  • Do you think this PR requires additional review of its security implications for other reasons? No.

What Needs to Be Merged and Deployed Before this PR?

No dependencies

Any Migrations?

• Yes, there are migrations
  • The migrations should be run PRIOR to the code being deployed
  • The migrations should be run AFTER the code is deployed
  • There is a more complicated migration plan (downtime, etc)
• No migrations

Submitter Checklist

I have gone through and verified that...:

• This PR is reasonably limited in scope, to help ensure that:
  1. It doesn't unnecessarily tie a bunch of disparate features, fixes, refactorings, etc. together.
  2. There isn't too much of a burden on reviewers.
  3. Any problems it causes have a small "blast radius".
  4. It'll be easier to rollback if that becomes necessary.
• I have named this PR and its branch such that they'll be automatically be linked to the (most) relevant Jira issue, per: https://confluence.atlassian.com/adminjiracloud/integrating-with-development-tools-776636216.html.
• This PR includes any required documentation changes, including README updates and changelog / release notes entries.
• All new and modified code is appropriately commented, such that the what and why of its design would be reasonably clear to engineers, preferably ones unfamiliar with the project.
• All tech debt and/or shortcomings introduced by this PR are detailed in TODO and/or FIXME comments, which include a JIRA ticket ID for any items that require urgent attention.
• Reviews are requested from both:
  • At least two other engineers on this project, at least one of whom is a senior engineer or owns the relevant component(s) here.
  • Any relevant engineers on other projects (e.g. BFD, SLS, etc.).
• Any deviations from the other policies in the DASG Engineering Standards are specifically called out in this PR, above.
  • Please review the standards every few months to ensure you're familiar with them.

[sharonfruit]

Happy to add any other changes in here not related, since I'm already editing. Still working on where the synth data comes from so will add that info in the work for the other open ticket.

[dtisza1]

This looks good to me!

• It tested well to create test users locally.
• The updates to the README.md look great!

This will be more flexible for us to use, with being able to provide those options via command line now.

Good work on this!

[ajshred]

Good job!