Enhancements to Macro Examples

### Description

- [x] Add unit tests @Matejkob #2163
- [ ] Make implementations of all macros consistent
- [x] Change nodes modification to use variable setters instead of `with` approach @Matejkob #2278
- [ ] Add DocC tutorials for Accessor Macros
- [ ] Add DocC tutorials for Declaration Macros
- [ ] Add DocC tutorials for Expression Macros
- [ ] Add DocC tutorials for Extension Macros
- [ ] Add DocC tutorials for Member Macros
- [ ] Add DocC tutorials for MemberAttribute Macros
- [ ] Add DocC tutorials for Peer Macros
- [ ] Add an example of Accessor Macro
- [ ] Add an example of Declaration Macro
- [x] Add an example of Extension Macro @Matejkob #2305