Show current running task

When user have many tasks configured, it becomes harder to find the current running task to stop it or enter note for the task entry.

If this setting is enabled, we will show "current running task" on the top of the "today" tab, below the daily overview section.

If there is only one task entry running, user can tap the "Edit" button to edit the current running entry, or tap the "Stop" button to stop the current running task entry.

If there are more than one task entry running, user can tap the box, and choose whether to edit or stop the task entry.