[EC-272] Web workers using EncryptionService

[eliykat]

Type of change

- [ ] Bug fix
- [ ] New feature development
- [ ] Tech debt (refactoring, code cleanup, dependency upgrades, etc)
- [ ] Build/deploy pipeline (DevOps)
- [ ] Other

Objective

This is a quick POC to illustrate what the web workers PR would look like extending EncryptionService instead of creating a new service.

This is rough and not for low-level feedback (the typing in particular is a bit rough) - just to consider the overall design of the services.

Code changes

• file.ext: Description of what was changed and why

Screenshots

Before you submit

• Please add unit tests where it makes sense to do so (encouraged but not required)
• If this change requires a documentation update - notify the documentation team
• If this change has particular deployment requirements - notify the DevOps team