Some examples are not tested properly

[Sliman4]

Just cloned the repo, tried to follow CONTRIBUTING.md, here's what I noticed:

• When you run ./run-tests.sh, it doesn't work because examples .wasm files are not built yet, and there's no notice that you should run examples/build_all.sh beforehand. Not sure what's the best way to fix it, since there is a build_all_docker.sh that may or may not be used in some cases.
• Some examples are not tested by CI, for example, examples/non-fungible-token fails to build tests because it doesn't use unit-testing feature of SDK, and examples/versioned has the same problem + uses deprecated UnorderedMap.

[frol]

@Sliman4 Would you be open to addressing these? I am happy to review and merge PRs

[Sliman4]

Some examples seem to be intentionally removed from gh actions (not sure why, but I guess there was a good reason), and I believe ci-test.sh is not referenced from anywhere, unless I don't understand something. I think it would be better if it was done by someone with more knowledge about CI, and specifically workflows of this repo, as I don't feel confident that I understand how and what is supposed to be tested, and don't have time to go through relevant commits, issues, and PRs