Request emails use the owner name instead of SenderName when both are present

[shuaick]

Bug description

Request-signature emails can use the owner's profile name in the from field even when the document already has an explicit SenderName.

Why this happens

In sendEmailToSigners, the from value is computed with an expression that mixes || and the ternary operator without grouping. In JavaScript, that means the condition is evaluated as (SenderName || useNameAsSender), so any truthy SenderName still routes to ExtUserPtr.Name instead of preserving the explicit sender name.

Expected behavior

If SenderName is set on the document, the outgoing request email should use that exact value in the from field.

Actual behavior

When both SenderName and ExtUserPtr.Name exist, the email can be sent with ExtUserPtr.Name as the display name.

Reproduction idea

1. Create a document where SenderName is set to a value different from the owner's profile name.
2. Send a signature request email.
3. Inspect the outgoing email from display name.
4. Observe that it uses the owner profile name instead of the explicit SenderName.

Impact

This can make request emails display the wrong sender identity, which is confusing for recipients and breaks expected mail customization.

[shuaick]

A fix is available in #2169.