Apply recipient search input on blur

[ChristophWurst]

Is your feature request related to a problem? Please describe.

As a Nextcloud user I might forget to submit the input in the to/cc/bcc fields and just click/tab to the message body. Right now that doesn't register my input as the value.

Steps to reproduce

1. Open the app
2. Click + New message
3. Enter [email protected]
4. Press Tab

Describe the solution you'd like

On NcSelect blur (lost focus), take current search input and add it as recipient.

In Jan's words (https://github.com/nextcloud/mail/issues/7149)

Tabbing out or unfocusing the field should also accept what was put in as recipient.

This makes perfect sense for email addresses in the NcSelect search field. Applying "Jane Doe" as recipient probably makes no sense.

Describe alternatives you've considered

N/a

Additional context

https://github.com/nextcloud/mail/issues/7149