[Transfer ownership] allow some more padding between labels and inputs

[wiswedel]

Padding between labels and inputs is currently quite narrow.

[wiswedel]

CC @nextcloud/designers

[jancborchardt]

Yup, setting to good first issue! :)

The changes have to be made in https://github.com/nextcloud/server/blob/master/apps/files/src/components/TransferOwnershipDialogue.vue, the CSS is at the bottom of the file.

[ChristophWurst]

Doesn't look like anyone picked up the good first issue. @jancborchardt mind fixing this for 18?