[DC-962]Send email to Research Users after they request snapshot access

[rjohanek]

Note: pausing on this work until duos integration with data exploration is figured out

Jira: DC-962

What:

1. Adds a notification for when a snapshot request submitted on terra through the cohort builder.
2. Updates readme.

Why:

So researcher users will receive an email with information about their request upon submission.

How:

Testing: The dependency on workbenchLibs was tested locally by using sbt publishLocal in workbench-notifications in workbenchLibs and then using the locally published snapshot version in thurloe.

Next: Once the workbench-libs and terra-helmfile PRs are merged, I can update the version of workbench-libs used here in thurloe, and then merge this change up and test the notification support in dev.

See also

https://github.com/broadinstitute/terra-helmfile/pull/5849
broadinstitute/workbench-libs#1701

---

• Submitter: Make sure Swagger is updated if API changes
• Submitter: If updating admin endpoints, also update firecloud-admin-cli
• Submitter: Update FISMA documentation if changes to:
  • Authentication
  • Authorization
  • Encryption
  • Audit trails
• Submitter: If you're adding new libraries, sign us up to security updates for them

[s-rubenstein]

LGTM