Canonicalization

[yhteoh]

• Please check if the PR fulfills these requirements

• The commit message follows our guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)
  feature

• What is the current behavior? (You can also link to an open issue here)
  Math canonicalization incomplete and not stored with math passes
  Atomic canonicalization incomplete

• What is the new behavior (if this is a feature change)?

• More robust MathExpr canonicalization
• Stored with other math passes
• Added variable substitution
• Enhanced simplification
• Implemented rule to resolve relative and absolute timing for AtomicCircuit
• Implemented rule to resolve hierarchical protocol into a SequentialProtocol of ParallelProtocol
• Implemented canonicalization of AtomicCircuit

• Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)
  No

• Other information:
  Incorporates Math Canonicalization #73

[benjimaclellan]

Looks good 👍🏼