fixes restcomm1786 added extension mocks and int test cases

[jaimecasero]

What this PR does / why we need it:
added extension mocks and int test cases

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

Special notes for your reviewer:

[abdulazizali77]

• looks good to me

[abdulazizali77]

Failures are consistent with master, Extension failures are expected
CallLifecycleTest potentially is unstable

org.restcomm.connect.testsuite.telephony.TestDialVerbPartOne.testDialApplicationInvalidURL
org.restcomm.connect.testsuite.extensions.BlockingExtensionTest.inboundSMPPBlocked
org.restcomm.connect.testsuite.extensions.OutboundBlockingExtensionTest.testOutboundSmsEndpoint
org.restcomm.connect.testsuite.extensions.OutboundBlockingExtensionTest.testOutboundSmsRcmlBlocked
org.restcomm.connect.testsuite.telephony.CallLifecycleTest.testDialClientAliceWithTimeLimit