[FRONT] create log-out option

[LeTrovoes]

depends on #9

upstream issue: AsyncPlanningPoker#119

❗️ Check the label before starting task, it depends on AsyncPlanningPoker#104 ❗️
Log-out is not yet implemented in the project. Once implemented, it's necessary to add the button on the sidebar and clear the localstorage token.

• (optional) (ux/ui) create button on sidebar

• (front) create button at the bottom of the sidebar with the proper backend request, also:

• remove token from localstorage.