Updating loop expressions in CLS

Featuring:
- Changing `Iterable` to `Iterable_Like` (incl. reverse var.)
- Specifying translations of iterable expressions to `.each` invocations
- Changing `while_loop` example to use `goto`, although tail recursion optimization would take effect anyway (maybe add that later)
- Adding optional label to generators
-- Including passing of the label to the `.each` invocations
- Specifying that `exhausted e` and `broken e` blocks are also passed to `.each/.map`
- Editing examples of generator expressions, adding one more (matrix transpose – tho matrix can have it’s own class…)