Fix custom-fields to support tags in Ticket Creation

[VishakhaShah]

What?

• This PR changes the way of passing custom_fields when a user wants to pass tags array along with it to create ticket.

Why?
-If we try to send tags along with custom_fields in post api call as mentioned in the example, it always gives datatype_mismatch error for tags even though tags is in Array datatype.

• Many users faced issue in passing tags array along with custom_fields in ticket creation for api call. There was no relevant example for this case.
  -So adding this change (to pass custom fields as separate dictionary variable) will resolve the user queries related to the errors occurring for datatype_mismatch in the above case.