Support dipole moments in ORCA (taken over !3020)

This MR is taken over from !3020 (closed) (made by @jfojt; thank you so much for the nice addition!) to add a dipole-moment parser for the ORCA output.

There are several remaining issues to be fixed in !3020 (closed), which are addressed in the present MR:

• There are 3 merge commits (9f47df72, d1e998c6, 3eb28afa) including inherited changes on several hundreds of files. These may be better not to be included in the master-branch history, and for that we probably need git rebase.
• As commented by @askhl (here), it should nowadays be avoided to add a big file to testdata, and it is instead now recommended to use a short string snippet to test a new functionality. To not inherit the big file in the commits in !3020 (closed), here it is also required to do git rebase.

In the beginning I wanted to simply update !3020 (closed) (following the guidance of Gitlab) via the forked repository jfojt/ase:fix-orca, but I found that probably I cannot update it when I did a full rebase. I therefore needed to open this as this new MR.

@askhl @AndrewRosen I would be very happy if you kindly review if this MR makes sense.

Closes !3020 (closed) (I will do by hand if the present MR is accepted.)

Checklist

• I am familiar with ASE's contribution guidelines.
• Doc strings in code changed in this MR are up to date.
• Unit tests have been added for new or changed code.
• Issue is resolved via "closes #XXXX" if applicable.