[web] Modify sidemenu

[Kuchteq]

• Add a section header "Groups" with a button to view all.
• Fetch the user's groups and display them in the list according to the figma.
• Below the groups list, add an "Add Group" button redirecting to the new create group page [web + server] Add group create functionality #12.
• Add a new subsection "Manage" with links to dashboard "/", account (TODO) and log out.