Some new features and improvements

[Mx-Iris]

This PR change is very large and is mainly used for RuntimeViewer application, which you can absolutely choose not to merge or partially merge.

• Change ClassDump related fields to ClassDumpRuntime to avoid confusion with the ClassDump project.
• Added comments for generating instance variable offsets.
• Some interoperability optimizations with Swift.
• Expanding structure member variables in the ObjC instance variables area (WIP).

This library is the core of RuntimeViewer and I will continue to add new features to it, here is what I think could be improved.

• Extract the same C structures into a separate file (Currently direct expansion of structure members is very distracting to read)
• Import the appropriate header files to make it work "out-of-the-box".

Finally, thank you very much for creating this library！

[leptos-null]

Thank you for publishing these changes and making a PR! I'm very glad this framework was helpful to you, and you integrated it into your app- I'm interested to take a look at that project.

I've not started reviewing this PR yet. Based on the size, I may pull some of these changes into the repo with smaller commits. I'll discuss here before doing that. I'll definitely set the git author on those commits to you, if I do that.

Thanks again!

[Mx-Iris]

@leptos-null I have completed the implementation of expandIvarRecordTypeMembers option and can now expand nested structures or unions

[leptos-null]

Thank you!

I'm thinking about breaking the changes up into these commits:

• Add addIvarOffsetComments to CDGenerationOptions
• Add expandIvarRecordTypeMembers to CDGenerationOptions
• Conform CDGenerationOptions to NSCopying
• Conform CDSemanticString to NSSecureCoding

Changes in this PR that I'm considering to not merge:

• Renaming the project from ClassDump to ClassDumpRuntime
  • I agree with the new name (it's a more unique name, and matches the name of this repository)
  • I want to check if this will break any existing projects as it's a rather large change
  • It looks like your renamed this very carefully throughout the project, including in the Makefile - thank you
• NS_REFINED_FOR_SWIFT for CDGenerationOptions
  • I think this is pretty cool
  • I want to learn more about the Swift side of this being in a different target
    • I know that it has to be in a different target since Swift and Obj-C cannot be in the same Swift package
    • It seems odd to me that a project could import ClassDumpRuntime and not import ClassDumpRuntimeSwift. Would CDGenerationOptions be usable in this case?

Other changes:

• Remove expand / indentLevel from CDRecordType
  • Move this logic into a new semanticStringForVariableName:indentLevel: method
    • I'm not sure exactly yet if expand also needs to be passed in
  • I do not think it is correct to put this information on the "type" itself, as "expand" does not directly relate to the type itself. I like the simplicity of your solution, for a somewhat complicated problem

(to be clear, I'm still thinking about some of these, just sharing them; I'll make all these changes, if I decide to, when I commit to this repo)