Add mass fraction functions to Modelica.Media

[wischhusen]

I made an attempt to resolve #3650. Please check.

[MartinOtter]

Could someone fix the conflicting files and check the result.

[dietmarw]

@hubertus65 and @wischhusen in order to be able to clean this up one would need a short description what the intended changes were so they can be isolated.

So please make a short list of which changes in which files should be part of the PR then I can attempt to isolate it.

[HansOlsson]

This PR is a total and utter mess!

• one commit is about an unrelated issue (Bug in the SharpEdgedOrifice for Loss factors #3944 [Bug in SharpEdgedOrifice for Loss factors resolved], and needs to be moved into a separate PR:
• the other commit is has a few relevant changes, and plenty of unrelated ones to this PR, i.e. dozens of changes outside of Modelica.Media.

And the unrelated changes seems to include changes of grounding in the electrical models. (Possibly that is due to conflicts - but why would there be changes at all in those models?)

[beutlich]

I recreated the original commit of @wischhusen from my local repository copy and also applied @dietmarw's and my change requests of the previous review. Hence, PR is clean again.

The root cause is that this PR was created by @wischhusen from master branch and kept open far too long. If then - months later - that master branch is updated by other commits, it will get messy for the open PRs. Two things that can be avoided: Don't create PRs from master branch and don't keep them unaddressed for long time!

[dzimmer]

I have now entered #4243 with some improvements, testing and based on the newest master of MSL. This PR should be closed without accepting the changes.

[beutlich]

Superseded by #4243.