Update relocation email notification copy

### Environment

SaaS (https://sentry.io/)

### Steps to Reproduce

Current email for relocation requests does not show source and target regions.

### Expected Result

Could we update the email to specify src and target region?

Sample copy:

Your relocation request has been accepted. You requested that the following org be moved from the _src region_ to the _target region_.
- _org slug_

Relocations usually complete within 24hours or less. If you do not hear from us, please contact support.

### Actual Result

Current email for relocation requests:

### Product Area

Org Relocation

### Link

_No response_

### DSN

_No response_

### Version

_No response_