Need a proper error handling mechanism in micro integrator

[GDLMadushanka]

Problem

Currently we are handling errors in mediation using the fault sequence. This is a global error catching a mechanism which catch all the errors. We need an improvement to support try-catch like fine grained mechanism to handle mediation errors.
Also we need a new method to throw an error from a mediation.

Proposed Solution

Introduce a mediator to throw errors from the mediation flow.
Add a new error hierarchy - similar to java
Implement the try catch mechanism using a new mediator.

Alternatives

No response

Version

4.4.0