Chore/76 improve pipelines caching and overall execution

[winqus]

Related Issues

Closes #76

Added Features / Changes:

• Improved workflow runtime (~1 min if package-lock.json wasn't changed, ~3 mins otherwise).
• Better caching settings (now installs npm packages if cache hit explicitly), workflows also run on develop (default) branch, to create a cache that can be used by sub-branches (e.g. feature/**).
• Set max run limit to 15 minutes (just in case, unlikely to be reached in near future).
• Set ubuntu version to 20.04 to be closer to the development version and to prevent unwanted changes if newer version is released (when using ubuntu-latest).
• Added concurrency settings (single same workflow execution at a time per branch) to make sure only the latest commit is running to not waste workers.

Referenced:

1. Control the concurrency of workflows and jobs. Run a single job at a time.
2. gh issue: Dependencies are still installed after cache flag is true
3. Restrictions for accessing a cache
4. Example using the cache action