SEO + SSR fixes: Fix <meta> tag syntax and add a basic test that SSR is working

[tdonohue]

References

• Relates to Fix issues with meta tags #1228 (earlier meta tag work)
• Relates to If there's no correlation ID cookie, server side rendering crashes #1279 and other recent work to fix SSR (server side rendering)

Description

This PR makes two small improvements for SEO + SSR. While these two improvements are not directly related, they are both necessary to improve SEO + SSR in version 7.0

1. First, modify the syntax of our <meta> tags slightly. Currently all meta tags use a property attribute (e.g. <meta property="" content=""/>) when they are supposed to use a name attribute (e.g. <meta name="" content=""/>) like in 6.x. This is a minor, but important, issue as the HTML5 <meta> tag only has a name attribute. See this good SO answer. See this commit for the change 7fcd055
2. Second, add a basic "smoke test" that server-side rendering is working properly to our GitHub CI build.yml. As you can see from the code, this "smoke test" looks for one of our <meta> tags in the server-side rendered output to verify that basic SEO + SSR is functioning.

Instructions for Reviewers

1. Check that <meta> tags now use name instead of property
2. Verify that "smoke test" of SSR works in GitHub CI
   • The initial version of this PR was created on main before If there's no correlation ID cookie, server side rendering crashes #1279 was applied. This resulted in failures of the SSR test. See this example: https://github.com/tdonohue/dspace-angular/runs/3164437546?check_suite_focus=true
   • However, now that If there's no correlation ID cookie, server side rendering crashes #1279 is applied to main, this PR's tests should succeed

[tdonohue]

I've verified the changes in this PR locally, additionally:

• All code changes are verified by specs
• GitHub CI changes are successful in this PR build process

Therefore, I'm going to merge this PR immediately in order to facilitate final testing this week, prior to 7.0. That said, if @artlowel or @atarix83 notice anything of concern tomorrow (in this PR or on the demo site), I will revert/fix as needed.