Add more operations to the Harvest node

[harshil1712]

The Harvest node currently doesn’t support the functionality to add task assignments to projects. One can also not add users to the projects via the node.

• Create a task assignment ref: Project Task Assignments – Harvest API V2 Documentation
• Project User Assignments ref: Project User Assignments – Harvest API V2 Documentation

[Vincent_Carignan]

Thanks @harshil1712 ! We would use these operations to automate our project creation in Harvest, add the relevant tasks to those project based on the deal in our CRM, and assign relevant team members to the project.