printing enhancements, including user defined gates or circuits

[sesmart]

Describe the feature you'd like

For printing and visualization of circuits, should consider auto formatting by depth, and allowing for more customizable and modular expressions of gates and circuits. If possible, users could specify which representations are being displayed

• Maybe don't unroll user-defined gates / circuits
• Allow for more flexible renaming of operators
• Fix default circuit printing

Questions:

• Does this need barrier?