Implemented LazyIterable default toImmutable[List/Set/Bag] and unit tests

[fermendivilt]

Fixes #1587

The tests pass; if the implementation is not what was expected (or anything else) please let me know and I'll work on it :)

Had some problems along the way, mainly because of biz.aQute.bnd.annotation.spi, when I tried to run all the tests. I still don't understand my issue (maybe the fact that I am using IntelliJ and its JDK version manager?), but the solution was to add it to a module-info.java file.

[fermendivilt]

Uuuuhm I might require some help for this, I don't understand the error :s

[pzygielo]

• #1660