[server] Change order of messages when creating sidebar

Summary: After D806 sidebar source and create sidebar messages were displayed in wrong order. This diff fixes it

Test Plan: Create sidebar and check if messages are displayed in correct order

Reviewers: palys-swm, ashoat

Reviewed By: ashoat

Subscribers: ashoat, zrebcu411, Adrian, atul, subnub

Differential Revision: https://phabricator.ashoat.com/D821