Configure agent-node usage based on jenkins instance type

[Divyaasm]

Current agent node setup and initialization is confined to use all the supported agent types while creating a jenkins instance as part of stack creation.

• Reorganize the agent node types into three different types by separating into agent types used by release/test/build workflows, benchmark test-workflows and gradle check workflows.
• We should be able bring up a requested jenkins instance type as mentioned above, only with the necessary agent nodes required by the workflows using it.