#20 engine factories added
#20 fixed hidden character + removed old engine factory
#20 added store mappers to transform entities metadata into store ones
#20 added new top engine factory built on top of individual engine factories
#20 updated the bootstrap to the new way to load engines
#20 updated UT + added new ones
#20 updated demo
#20 updated the docs
Merge branch 'develop' into feature/engine-factories
Merge branch 'develop' into feature/engine-factories
#20 updated venus annotations to leverage code coverage
Close #20 Merge branch 'feature/engine-factories' into develop