As a staff, I can select "no notification", so that the client is not notified of the Name Request confirmation, or results

### Background

When staff request a name for a client, sometimes it is because they were supposed to do something for them but the NR expired, so we need to get a replacement for them. In these situations, we don't need to tell them about the name request submission or examination - it may just confuse them.
NRO has the ability to not send notifications to the client about this NR. This ticket is to build that.

### AC
#### Scenario 1 - dont sent
GIVEN I am a staff member
WHEN I request a name for a client
THEN I can indicate that I don't want the client to receive any notifications (submission confirmation, or results)
AND I I don't have to enter an email address

#### Scenario 2 - send
GIvEN I am a staff member
WHEN I request a name for a client
THEN I can indicate that I DO want to send the client notifications
AND I can enter the email of the client that will be receiving the notifications

#### Scenario 3 - as client
GIVEN I am a client
WHEN I request a name
THEN I **cannot** opt out of receiving notifications (can't see the option that staff see)

The acceptance scenarios define separate staff and client name-request behavior, but the issue names no files, tests, or entry points. Start by locating the staff/client name-request flows and notification handling, then trace how email requirements are enforced. Done means staff can choose whether to notify and omit the email when opting out, while clients cannot see that option.

Written by the indexing model from the issue text.