Save Username in Local Storage only at Permission

[Nomandes]

Save Username in Local Storage only at Permission

Issue: #225

Acceptance Criteria

• When entering a room, a checkbox with a label "Persist username" is visible
• Hovering the checkbox and label shows a explanation text
• The checkbox is initially unchecked
• The checkbox state is persisted in local storage
• The checkbox state in local storage is applied at future sessions
• When the checkbox is checked, the username is persisted in local storage

Description

The local storage of the username is now only applied if the checkbox is checked. The state handling was extracted in its own hook and the textfield with checkbox in its own module to be reused in the create session and join session dialogs.

[NearW]

Tested it locally: Works fine :)