feat(admin_obligation_types): Admin apis to create, delete and get obligation types

[deo002]

Changes

• Added admin APIs to create, delete and get a list of obligation types.
• POST /obligations/types: Creates a new obligation type if not already present. It must be non-empty and uppercase. If the obligation type to be created is already in db with 'active' flag set to false, it is changed to true.
• DELETE /obligation/types/{type}: The {type} is soft-deleted if it exists in db, has 'active' flag set to true and no obligation references it.
• GET /obligations/types: Fetches a list of all obligation types. Flag 'active' can be set to false to fetch the inactive types.
• During obligation creation and updation, associate them with only active obligation types.

Submitter Checklist

• Includes tests (if there is a feature changed/added)
• Includes docs ( if changes are user facing)
• I have tested my changes locally.

[GMishx]

Tested, working as expected.