Add synapse unit testing framework

[sajithaliyanage]

Provide a built-in way to execute a unit test against a given synapse configuration artifact such as sequence, proxy, api, local entry, endpoint.

Following tasks will be added from this PR,

• Test Proxy services with test cases, input payloads and transport properties
• Test APIs with test cases, input payloads and transport properties
• Test Sequences with test cases, input payloads and synapse, axis2, transport properties
• Undeploye all the deployed configurations
• Customize the starting port of unit testing framework

[vanjikumaran]

@isudana we should look into this feature

[AnasAltarazi1998]

@sajithaliyanage

it's great job bro,
I think they should merge it.
anyway I suggest you to provide more dynamic resolver for actual value to support the following form :
$body/tagName/tgaName....etc
it will help more for testing really actual values.

[isudana]

@sajithaliyanage Will you be able to resolve the conflicts and update the PR?

[sajithaliyanage]

@sajithaliyanage Will you be able to resolve the conflicts and update the PR?

@isudana I resolved the conflicts. please review and merge.