72 tasks add tasks app package to prodid (#73)

* Moved `userAgents` declaration to `ICalendar`

Signed-off-by: Arnau Mora <arnyminer.z@gmail.com>

* Moved `PRODID` generation to `ICalendar`

Signed-off-by: Arnau Mora <arnyminer.z@gmail.com>

* Loading `userAgents` from `populateTask` from `taskList.provider`

Signed-off-by: Arnau Mora <arnyminer.z@gmail.com>

* Added companion `prodId(List<String>)`

Signed-off-by: Arnau Mora <arnyminer.z@gmail.com>

* Using new `ICalendar.prodId()`

Signed-off-by: Arnau Mora <arnyminer.z@gmail.com>

* Added jtx package name

Signed-off-by: Arnau Mora <arnyminer.z@gmail.com>

* Updated `testWrite` with the proper `prodId` of the task

Signed-off-by: Arnau Mora <arnyminer.z@gmail.com>

* Use jtx Board package name constant

Signed-off-by: Arnau Mora <arnyminer.z@gmail.com>
Co-authored-by: Ricki Hirner <hirner@bitfire.at>