allow access to part from elements

[tomjebo]

With this change, it's possible to do this:

OpenXmlPartRootElement partRoot = pShape.Ancestors<OpenXmlPartRootElement>().First();

if (partRoot.OpenXmlPart is null)
{
    Console.WriteLine("partRoot is null");
    return;
}

OpenXmlPart part = partRoot.OpenXmlPart;

[github-actions]

Test Results

     108 files  ±0       108 suites  ±0   1h 15m 4s ⏱️ -22s
  2 011 tests ±0    2 008 ✔️ ±0    3 💤 ±0  0 ❌ ±0 
48 006 runs  ±0  47 952 ✔️ ±0  54 💤 ±0  0 ❌ ±0 

Results for commit 620b874. ± Comparison against base commit f697af4.

[tomjebo]

@ashahabov Please take a look at this. I think this would meet your needs based on your StackOverflow question.

[twsouthwick]

LGTM - do we want this in v3?

[tomjebo]

LGTM - do we want this in v3?

yeah, I think that'd be nice.

[tomjebo]

@twsouthwick regression test I guess would be to make sure the property doesn't go back to full internal or private. not sure if we really need a test though.

[twsouthwick]

No that's not needed. We'll catch that in review