Investigate visible=False for shared dependencies

[memsharded]

Follow up from #14721. Check the implications of expanding requires with visible=False for re-packaging when dependencies are shared libs

Issue about re-package concept: #13171

[memsharded]

I think at the moment it is fine:

• If dependencies are direct, they will match because libs=True and headers=True
• If transitive dependencies are shared libraries too, they will match because run=True

The only problem comes from the scenario:

• Multiple direct shared dependencies
• These shared dependencies depend on different versions of the same library, linked as static
• Users wanted to have a conflict because of these static libraries (conflict will not be raised, and user needs to explicitly override=True to define the same transitive dependency)

Users need to understand these aspects, making a shared dependency visible=False is pretty unusual, and should only happen in the case of re-packaging, so lets wait until #13171 is addressed.

I am closing this issue as not-an-issue, and lets follow up on the re-package ticket