Rename all the API endpoint names of actions and events to have underscore

[ishantiw]

Description

Update separator to "_" from “:” because in JSON RPC, method should be using the characters allowed for method definition. Namespace is often separated with _ (underscore) in other projects such as web3.

Example, app_getNodeStatus, app_getConnectedPeers, namespace_methodName

Acceptance Criteria

• All tests in the framework and framework-plugin should pass
• Modify regular expression for module and plugin name to not to have _(underscore)

Additional Information

• Related Improve framework on-chain architecture to support new state model #6554