Allow to include in-package dependencies when duplicating

[ceraolo]

This is a companion ticket of #4536.
Now that #5733 is solved, I expect that someone starts working on #4536.
I would like to focus on a nasty issue that, in my opinion, has been plaguing Dymola for years, and maybe can be addressed in OM from the ground up when working on #4536.

Consider Package1. Suppose we want to copy Model1 into Package2. Therefore we duplicate into Package2.

If common duplication is done, i.e. Dymola's and OM's (once #4536 is solved) this would create a dependency of Package2 on Package1 which not always is welcome. It also stays hidden and annoys non-expert (but also expert) users.
In fact, if one unloads Package 1 and opens Model1 in Package 2, a red-box appears in the place of subMod in Package2.Model1.

What I suggest is to allow, as an option, to "include in-package dependencies". I this case, duplicating Model1 should automatically duplicate also SubModel1.

The implementation should take care of the package structure. For instance, when duplicating Model2 into Package2, not only Model2 should be duplicated, but also SubModel2, which should be inserted into SubPackage1; the latter, if not existing, should be created.

Note that this is not in contrast with #4536. According to this proposal, all dependencies on libraries (i.e. packages different from the one we are duplicating from) should be dealt with exactly as #4536 asks for.