…1325)

Replace the warning-as-exception checks with use of `pytest.warns()`.

That is more semantically correct and works correctly when the tests
are run without -Werror (e.g. because -Werror tends to cause test suites
to crash on irrelevant deprecation warnings from other components).

While at it, replace the homegrown exception checks in test_orientations
with `pytest.raises()`.

Fixes #1340

Error detected during analysis of #1280

Bug Fixes (BUG):
-  Fix Error in transformations (#1341)
-  Decode #23 in NameObject (#1342)

Testing (TST):
-  Use pytest.warns() for warnings, and .raises() for exceptions (#1325)

Full Changelog: 2.10.6...2.10.7