vcard staging polishing needed

[r10s]

thanks for making vcard nicer at https://github.com/deltachat/deltachat-desktop/pull/3948

there are some minors that did not make it to the PR review:

• staged vcards show the "pointing finger cursor", which does not make sense as nothing happens when tapping the vcard

• there is no padding left of the vcard's avatar, which looks bad. i'd add same padding as above the vcard's avatar

EDIT: same is true for staged files (the missing padding does not look so bad in case of files, the cursor is wrong as well), so, in case both share the same code, that can be fixed together

[Simon-Laux]

even with those suggestions it will still really not look good, would be better to also give it a slight background, margin, padding and rounded corners IMO

[r10s]

surely one can improve beyond fixing the most obvious design bugs.

the two points are the minimum to not consider the design buggy - the result fits somehow to other staged item then - and there is no need to wait for "new composer"