Feature: Atomic numbered TaskIds from Hex-string TaskIds

Create Atomic numbered TaskId to replace the currently used Hex string TaskId

Description:
Presently, we are showing TaskIds in the tasks page as the identifier. As hex strings aren't that recognisable thus will be using alias-mapped numbering which will be incremented atomically as tasks are added.

Tasks:

1. Create a new field TaskNumber that will be incremented as new tasks are created and added.
2. Add this TaskNumber field to all existing tasks, valued chronologically.

Additional Information:

• Run a cloud function to add the TaskNumber field.

Acceptance Criteria:

1. The current model should fetch the last task added and increment the task number for the new task
2. Task number must have prefix as abbreviation of the site that task belongs to. For example, task of status site can have an ID like #SS1234.