NcInputField should be submitted when using the Enter key

[GVodyanov]

Due to using the @trailing-button-click to submit the input, hitting the Enter key doesn't do anything, as it should in my opinion.

Also, due to the custom event, using min-length doesn't work, and you have to check whether there are any characters inputted in the triggered method.

Somewhat relevant to nextcloud/contacts#4039

[ShGKme]

submit is an event of a form element, not an input element. So using Enter for submitting is a form's feature.

trailing-button-click doesn't always mean "submit". It might be "clear", for example.

If we want to add an ability to submit by trailing button, we may add a way to provide nativeType to NcButton of the trailing button. Then we can use submit natively.