feat(cli): switch .template to .ejs

[virkt25]

Switch .template to .ejs for CLI template files. Gives us syntax highlighting instead of error in VSCode.

Follow up from #991

Checklist

• npm test passes on your machine
• New tests added or existing tests modified to cover all changes
• Code conforms with the style guide
• Related API Documentation was updated
• Affected artifact templates in packages/cli were updated
• Affected example projects in packages/example-* were updated

[bajtos]

I am not able to judge the impact of the changes project-generator.js, but I don't see any obvious problem.

FWIW, LGTM.

Please get somebody more familiar with our CLI package to approve your changes too.

[bajtos]

I am not a fan of making unrelated changes. Can you at least split the removal of dist6 entries into a standalone commit please?

[bajtos]

Ditto.

[virkt25]

@bajtos Feedback applied. See #998 for template changes unrelated to name.

[jannyHou]

@virkt25 there is no test need to upgrade? like compare file name. I am not quite familiar with the cli package, may not be a valid concern, feel free to ignore if tests are good :-p

[b-admike]

Same concern as Janny, otherwise LGTM.

[virkt25]

Current tests assert that most of the files that have been renamed exist in a generated project (with actual name not with .ejs and check contents (usually a line not entire file contents). So I believe we are covered. You can find those tests in packages/cli/test/project.js, app.js, and extension.js in same folder as first test file.