Add bio fields (#6645)

* Add bio fields

- Fix #3211
- Fix #232
- Fix #121

* Display bio fields in web UI

* Fix output of links and missing fields

* Federate bio fields over ActivityPub as PropertyValue

* Improve how the fields are stored, add to Edit profile form

* Add rel=me to links in fields

Fix #121

app/services/activitypub/process_account_service.rb

@@ -70,6 +70,7 @@ class ActivityPub::ProcessAccountService < BaseService
     @account.display_name            = @json['name'] || ''
     @account.note                    = @json['summary'] || ''
     @account.locked                  = @json['manuallyApprovesFollowers'] || false
+    @account.fields                  = property_values || {}
   end
 
   def set_fetchable_attributes!
@@ -126,6 +127,11 @@ class ActivityPub::ProcessAccountService < BaseService
     end
   end
 
+  def property_values
+    return unless @json['attachment'].is_a?(Array)
+    @json['attachment'].select { |attachment| attachment['type'] == 'PropertyValue' }.map { |attachment| attachment.slice('name', 'value') }
+  end
+
   def mismatching_origin?(url)
     needle   = Addressable::URI.parse(url).host
     haystack = Addressable::URI.parse(@uri).host