EPIC - Drop legacy runtime and KieAssemblerService Drools integration

[elguardian]

Removing DROOLS jBPM Integration.pdf

At present kogito is based on the premise of a combination of code
generation based on a fluent interface. Nothing at kogito level uses
these parts of KieAssemblerService anymore.
This is causing not moving those test/guards for the functionality in
the new infrastructure causing a few problems:

• Functionality loss because those tests are not using the new
  infrastructure of fluent interface and code generation.
• Create the illusion that those tests are of any use for the current
  system and make the system weaker
• making the functionality gaps less visible.

The proposal would do:

1. remove the assembler services and relieve drools from the use of
   that infrastructure
2. remove the old runtime that is only useful for these tests.

This should lead to:

1. focus only in the fluent interface and codegen
2. remove unused parts and make the system leaner
3. identify all the missing parts at level functionality to reduce the gaps
4. increase the level of guards at codegen level and fluent interface.

Test consolidation

• Move tests and create infrastructure to move old legacy v7 tests to kogito. #1103
• Removing fluent interface from DROOLS kie api #1186
• Move Tests where DRL or DMN are used in combination with BPMN #1130
• Migrate process test migration from v7 legacy runtime to code generation #1131
• Remove unused bpmn in jbpm-test #1277

v7 features migration

• EPIC - V7 Features forward port #1132.

[elguardian]

WIP
apache/incubator-kie-kogito-runtimes#3451

isolate for now the test.
Now working on moving those test to codegen

[elguardian]

• Test moved to another folder
• creating now mojo to generate the code on those tests and it does not depend on kogito but jbpm only (jbpm-flow-builder)

[elguardian]

• maven plugin finished. now anything in src/main/bpmn will create an static executable process.

[elguardian]

• Identify some gaps between v7 and kogito functionality lost.

transformers
assignments
errors
associations
conditionals
collaboratins.

• migrating test to new kogito runtimes.