put "bio" into the vcard

[r10s]

in various 1:1 discussion, we agreed that we want to put the "bio" to the vcard as well.

beside transport-information (address, key), with that change, the vcard contains all "open to all contacts" information from the user's profile - up to now, avatar/name was in vcard, but bio was not.

second part of this issue, on importing a vcard, of course, these information should go to the contact record as name/avatar.

having these information earlier, allows us eg. to show them already before sending a message; this is useful esp, for bots. but that also is useful for normal contacts. and, even without UI changes, the information would be available in profile earlier.

[link2xt]

There is likely no existing property for a signature in a vCard, but it can go into NOTE which is very similar: https://www.rfc-editor.org/rfc/rfc6350#section-6.7.2