fix #10728:Add ability to rename part title

[salilkhandelwal]

The part title is no longer grayed out and we are able to rename it .

[Jojo-Schmitz]

As I wrote in the issue tracker:
Looks like a very easy one-line fix. Except that it doesn't work:

• the name in the part's tab doesn't change
• the filename when exporting the part doesn't change
• the partname text in upper left Corner of the title frame of the part doesn't change
• the meta- tag partName doesn't change

Only thing that does change is what is shown on the excepts dialog. And even that doesn't survive a save/close/reopen!

[salilkhandelwal]

Yes , I will work on it , did not notice so many loop holes

[Rockettwo]

Hey,
are you still working on this or would it be okay, if I'll stick to this? Or do you need some help?

[lasconic]

I close this PR. It needs a lot more work.