Spliting BeanManager for CDI Lite

[antoinesd]

We should create a new BM interface containing methods supported by lite only.
The current BM would be accessible by extending this lighter BM and add the missing methods for Full.

[manovotn]

I have sent a draft of what it could look like. I suppose we'll discuss it in the next meeting (23rd March) and OFC any feedback on the PR or here is welcome as well.

[manovotn]

Solved via #471.
We can adjust it further if needed but we want something in to be able to cut first Alpha releases.