Use both task ID and job ID as primary keys and refactor to use $addLoi as the task ID.

[sufyanAbbasi]

Fixes #2275

Removes dependency on the isAddLoiTask field on the task and uses the convention of $addLoi as the marker for LOI tasks. Also reformats all of task local DB and sub tables to use both task_id and job_id as primary keys to prevent conflict.

• Removes references to isAddLoiTask on the task, instead declares a helper method conveniently called isAddLoiTask().
• Detect LOI tasks by looking for the $addLoi prefix.
• Uses both the task ID and job ID to build relationships between task tables in order to prevent task ID conflicts.

• Created three survey types: adhoc, predefined, and mixed, and verified that each works as intended.

PTAL @gino-m @shobhitagarwal1612

[gino-m]

Composite PKs to the rescue!

[gino-m]

The original FR is now obsolete so closing for now. Sorry for the churn!