Cherry-pick of the following PRs:

• [ExtractAPI] Include +/- symbols for ObjC methods llvm/llvm-project#145035: ObjC methods include a +/- prefix to indicate if they are a class or instance method. This information is valuable, and must be included in the navigator generated by ExtractAPI. rdar://150870936
• [ExtractAPI] Include virtual keyword for methods llvm/llvm-project#145412: This information was being left out of the symbol graph. rdar://131780883
• [ExtractAPI] Include tilde in destructor name llvm/llvm-project#146001 The subheading for a destructor contained only the identifier. The tilde must also be included as it is necessary to differentiate the destructor from any constructors present. rdar://129587608
• [ExtractAPI] Format pointer types correctly llvm/llvm-project#146182: Pointer types in function signatures must place the asterisk before the identifier without a space in between. This patch removes the space and also ensures that pointers to pointers are formatted correctly. rdar://131780418, rdar://154533037