[web] Display sidebars inline

Test Plan: Check if sidebars are displayed inline correctly, if pressing navigates to correct sidebar and if styling matches native

Reviewers: ashoat, palys-swm

Reviewed By: ashoat

Subscribers: zrebcu411, Adrian, atul, subnub, karol-bisztyga

Differential Revision: https://phabricator.ashoat.com/D681