Validate type of dimensions in test generator

This change
- adds "dimensions" type validation in the test generator,
- fixes incorrect usages,
- adds new control flow and QLSTM tests that were previously omitted
  due to this bug,
- refactors QLSTM tests for readability and ease of maintenance, and
- updates README to use the new type format.

Fix: 151217992
Test: generate_all_tests.sh
Test: NNT_static
Change-Id: I55b47a7ff02cb5ec25150d6be322ee3dbe9dcf43
15 files changed