Created new processing structure in InterceptorExtension

* Processing Class- and Methodlevel InterceptorBindings
* Updated javadocs
* Created testcase 'TestEJBInterceptedMethodLevel.java'
* Improved testcase 'EJBWithExludeClassInterception'
* Implemented testcase 'TestEJBInterceptedMethodLevel'
Organized Test infrastructure code

* Separated testing components in distinct packages ('extension')
* Introduces package 'utils' containing ['Entities', 'Exceptions', 'Mocks']
* Removed 'demo test package'
* Introduced subpackage 'resources' holding sample bean definitions
Refactoring of the extension layer

* Pulled up field 'processAnnotatedType' into BaseExtension
* Implemented new testcase 'Method and class level interception'
* Javadoc updates
* Added setup methods to reset 'isInvoked' flag in DummyInterceptor
* Removed redundant resource 'ExcludeInterceptor'
* Improved test case 'TestInterceptedBean': Now asserting actual Interceptor invocation during test execution
Larger refactoring of InterceptorExtension and infrastructure code

* Renamed InterceptorWrapper -> EjbInterceptorWrapper (leads to better understanding of the IDEA)
* Renamed extension SPI event handler
* Extracted EjbInterceptor modification in a method object
Introduced new EjbInterceptor design model

* Designed and implemented new components: InterceptorWrapperBinding, InterceptorWrapperRepository
* Implemented new testcase 'TestEjbInterceptionSequence'
New approach regarding the interceptor calling/delegation mechanism based on creation of a custom InterceptorInvocationContext

* Implemented creation of custom InterceptorInvocationContext containing the rearranged InterceptorChain
* Updated javadocs
* Minor code refactorings