Search for PrivacyRequest based on hashed identity [#765]

[seanpreston]

Purpose

This PR adds exact match searching for identities.

Changes

• adds identity query param to get_request_status API view
• upon receiving an identity param, we hash the value with ProvidedIdentity.hash_value(...) then search the ProvidedIdentity table for a matching hashed value
• we then add any matching ProvidedIdentity.privacy_request_id values to the main query.filter(...) search, so as to maintain compatibility with other filters

Checklist

• Update CHANGELOG.md file
  • Merge in main so the most recent CHANGELOG.md file is being appended to
  • Add description within the Unreleased section in an appropriate category. Add a new category from the list at the top of the file if the needed one isn't already there.
  • Add a link to this PR at the end of the description with the PR number as the text. example: #1
• Applicable documentation updated (guides, quickstart, postman collections, tutorial, fidesdemo, database diagram.
• If docs updated (select one):
  • documentation complete, or draft/outline provided (tag docs-team to complete/review on this branch)
  • documentation issue created (tag docs-team to complete issue separately)
• Good unit test/integration test coverage
• This PR contains a DB migration. If checked, the reviewer should confirm with the author that the down_revision correctly references the previous migration before merging
• The Run Unsafe PR Checks label has been applied, and checks have passed, if this PR touches any external services

Ticket

Fixes #765

[TheAndrewJackson]

LGTM. That's an interesting use of column to get back the ids. I haven't seen it before.