Mobile: show Homepage contents and avoid duplicate menus

Summary:
After this change, the Homepage finally shows contents on Mobile,
instead of just showing the sidebar menu twice.

Closes T15216

Test Plan:
To test this change in general:

• resize the window horizontally and enjoy

I tested it in:

• tested homepage of Phorge
• Audit
  • tested homepage of Audit
• Auth
  • tested Auth homepage
  • tested Login page
  • tested Forgot your password page
• Config
  • tested Config homepage
  • tested page Core Settings
  • tested page Unresolved Setup Issues
  • (Services)
    • tested page Database Status
    • tested page Cache Status
    • tested page Notification Servers
    • tested page Repository Services
    • tested page Search Servers
  • (Extensions/Modules)
    • tested page Constants: Differential
    • tested page Content Sources
• Conpherence
  • tested open-close menu
  • tested persistent chat
  • tested Rooms list
  • tested single Chat
• Dashboards
  • tested general homepage of Dashboards
  • tested specific Dashboard - view page
  • tested specific Dashboard - edit page
• Differential
  • tested general homepage of Differential
  • tested Create Diff page
• Diffusion
  • tested general homepage of Diffusion
  • tested specific Diffusion repository - view page
  • tested specific Diffusion repository - Manage page
  • tested specific Diffusion repository - Policy page
  • tested specific Diffusion repository - Automation page
  • tested specific commit page - view page
  • tested specific commit page - Edit Commit
• Diviner
  • tested general homepage of Diviner
  • tested specific Diviner book
  • tested list of technical Classes
  • tested specific technical Class
  • tested search of All Atoms
• Feed
  • tested Feed homepage ("All Stories")
  • tested specific feed - view page
• Files
  • tested general homepage of Files
  • tested specific File - view page
  • tested specific File - Edit File
  • tested Award Token popup
  • tested Flag for Later
  • tested View Transforms
• Form Engine
  • tested View Forms Configurations page
  • tested specific View Form Configuration
  • tested Use Form
• Maniphest
  • tested general homepage of Maniphest
  • tested specific Maniphest Task - view page
  • tested specific Maniphest Task - Edit mode
  • tested specific Maniphest Task - Award Token popup
• Menu
  • tested page Configure Menu
  • tested page Personal Menu Items
  • tested page Global Menu Items
• Notifications
  • tested open action
  • tested close action
  • tested click action
• People
  • tested general homepage of People
  • tested specific User - view page
  • tested specific User - Settings page - home
  • tested specific User - Settings page - Date & Time
  • tested specific User - Settings page - External Editor
  • tested specific User - Settings page - External Editor
  • tested specific User - Settings page - SSH Public Keys
  • tested specific User - Settings page - SSH Public Keys - upload popup
  • tested specific User - Settings page - SSH Public Keys - view history
• Pholio
  • tested general homepage of Pholio
  • tested Create a Mock page
  • tested specific Pholio - view
  • tested specific Pholio - Edit page
  • tested specific Pholio - Award Token popup
  • tested specific Pholio - Edit Related Tasks popup
  • tested specific Pholio - add a Comment
• Phriction
  • tested specific page of Phriction - view
  • tested specific page of Phriction - Create Page popup
  • tested specific page of Phriction - Create Page dedicated page
  • tested specific page of Phriction - Edit Page
  • tested specific page of Phriction - Award Token popup
• Project
  • tested general homepage of Projects
  • tested Create Project page
• Search
  • tested search results All Results
  • tested Advanced Search page
• TOTP
  • tested input screen
• Workboard
  • tested specific Workboard
  • tested Create Task popup
  • tested Add Column popup
  • tested Manage Workboard page
  • tested Edit Details page
  • test Flag for Later popup
  • test Edit Picture page

Reviewers: O1 Blessed Committers, Cigaryno, speck

Reviewed By: O1 Blessed Committers, Cigaryno, speck

Subscribers: avivey, speck, tobiaswiese, Matthew, Cigaryno

Tags: #mobile, #ux

Maniphest Tasks: T15216

Differential Revision: https://we.phorge.it/D25107