Generate `operator!=` for user-facing classes

[tmadlener]

BEGINRELEASENOTES

• Generate operator!= for all user facing handle classes to make constructs like !(lhs == rhs) obsolete.

ENDRELEASENOTES

• [x] Check for occurences in our tests (one occurrence only, switched in this PR)
• [x] Check if interface types need these as well (already have them)
• [x] tests

[jmcarcell]

I can't push to your branch:

tests/read_test.h
84:    if (!(hits[1] == hitRefs[0] && hits[0] == hitRefs[1])) {
153:  if (!(d0 == mcps[2])) {
156:  if (!(d1 == mcps[3])) {
159:  if (!(d2 == mcps[4])) {
162:  if (!(d3 == mcps[5])) {
174:  if (!(d0 == mcps[6])) {
177:  if (!(d1 == mcps[7])) {
180:  if (!(d2 == mcps[8])) {
183:  if (!(d3 == mcps[9])) {
225:        if (!(mcpRefs[i] == mcps[2 * i + 1])) {
230:        if (!(mcpRefs[i] == moreMCs[index])) {
328:        if (!(nmsp.ref().getObjectID() == cpy.ref().getObjectID())) {
337:        if (!(it->getObjectID() == cpy_it->getObjectID())) {

If you use the amazing ast-grep changing this can be as easy as:

$ ast-grep -p '!($A == $B)' -r '$A != $B' tests/read_test.h -U