Add iterator methods to container-like classes

[jslee02]

Summary:

• Add iterator methods (i.e., each*()) to addresses Consistent interface of container class for element access #613.
• Deprecate MetaSkeleton::get{BodyNodes,Joints,Dofs}() and BodyNode::getShapeNodes[With]() in favor of *::each*()
• Add {MetaSkeleton,BodyNode}::set{Color,Alpha}()

Here is an example of changing the alpha value of a skeleton before and after the change:

// Without the change
for (auto i = 0u; skel->getNumBodyNodes(i); ++i)
{
  auto body = skel->getBodyNode(i);
  for (auto& shapeNode : body->getShapeNodesWith<VisualAspect>())
    shapeNode->getVisualAspect()->setAlpha(0.5);
}

// With the change
skel->eachBodyNode([](BodyNode* body) {
  body->eachShapeNodeWith<VisualAspect>([](ShapeNode* shapeNode) {
      shapeNode->getVisualAspect()->setAlpha(0.5);
  });
});

// or
skel->setAlpha(0.5);

---

Before creating a pull request

• Document new methods and classes
• Format new code files using ClangFormat by running make format
• Build with -DDART_TREAT_WARNINGS_AS_ERRORS=ON and resolve all the compile warnings

Before merging a pull request

• Set version target by selecting a milestone on the right side
• Summarize this change in CHANGELOG.md
• Add unit test(s) for this change

[codecov]

Codecov Report

Merging #1644 (c67aa60) into main (5ef8c1f) will decrease coverage by 0.00%.
The diff coverage is 77.61%.

@@            Coverage Diff             @@
##             main    #1644      +/-   ##
==========================================
- Coverage   59.12%   59.12%   -0.01%     
==========================================
  Files         493      494       +1     
  Lines       40714    40766      +52     
==========================================
+ Hits        24072    24101      +29     
- Misses      16642    16665      +23     

Impacted Files	Coverage Δ
dart/dynamics/BodyNode.hpp	100.00% <ø> (ø)
dart/dynamics/MetaSkeleton.cpp	44.88% <0.00%> (-0.72%)	⬇️
dart/dynamics/MetaSkeleton.hpp	100.00% <ø> (ø)
dart/dynamics/detail/BasicNodeManager.hpp	27.65% <ø> (ø)
dart/utils/DartResourceRetriever.hpp	100.00% <ø> (ø)
dart/utils/PackageResourceRetriever.hpp	100.00% <ø> (ø)
dart/dynamics/BodyNode.cpp	78.83% <24.00%> (-0.96%)	⬇️
dart/collision/detail/CollisionGroup.hpp	70.00% <80.00%> (-1.12%)	⬇️
python/dartpy/dynamics/MetaSkeleton.cpp	54.50% <85.71%> (+0.23%)	⬆️
dart/dynamics/detail/BodyNode.hpp	96.62% <96.42%> (-0.97%)	⬇️
... and 9 more