Create a merchant config for enable `pg_agnostic_mit`

[ShankarSinghC]

Create a merchant config (pg_agnostic_mit) to enable usage of Network Transaction/Reference ID in recurring mandate payments. This will be a business profile level config that a merchant specifies.

API Spec:-

POST /business_profile/{bp_id}/configs/pg_agnostic_mit
{
    “enabled”: true,
}

[tinu-hareesswar]

Can we not store this under mandate? and the endpoint also lets make it something like pg_agnostic_recurring?