Run init task with keyboard shortcut

[puengel]

Instead of always running an init task (or always running init-once on startup) run init task only when explicitly required by user.

Steps:

• bob run [task]
• build tasks will be build
• run tasks will be started
• NO INIT TASKS WILL BE STARTED BY DEFAULT
• switch to task in TUI and hit ctrl+i
• Init task for this task will be executed

This will also bring the benefit that such an init task can be run multiple times. E.g. one could reset his test data with this init task.