DMN17 — Iteration context not allowed in quantified expressions

Currently, the grammar allows to use iteration context only in case of the for loop. However, quantified expressions (some, every) are very similar in their nature, so there is no good reason for inconcistency there. This leads to overly verbose expressions, e.g.

some i in (for j in 1..10 return j) satisfies j > 5

. One cannot simply write

some i in 1..10 satisfies j > 5

.