The namespace of the `ReceiverController` class was updated from `EnvelopeGenerator.GeneratorAPI.Controllers` to `EnvelopeGenerator.Server.Controllers`.
The `Get` method was enhanced with the following changes:
- Added `[Authorize]` attribute with `AuthScheme.Sender`.
- Updated the method signature to include an optional `ReadReceiverQuery? receiver` parameter (defaulting to `null`) and a new `bool onlyEmailAddress` parameter (defaulting to `false`).
- Modified logic to handle `receiver` being `null` by creating a new `ReadReceiverQuery`.
- Added handling for `onlyEmailAddress` to return a list of email addresses if true.
- Simplified the result handling and removed the previous `receiver.HasAnyCriteria` logic.
Replaced "EnvelopeGenerator.WebUI" with "EnvelopeGenerator.Server" and "EnvelopeGenerator.WebUI.Client" with "EnvelopeGenerator.Server.Client". Updated project entries, solution configuration platforms, and nested projects to reflect these changes.
