feat: support erf_square and swap_phases

[yitchen-tim]

Issue #, if available:
closes #1018

Description of changes:
Add support to two pulse instructions:

• swap phases
• erf_square

Note: The code was reviewed in internal PR346

Testing done:
unit tests

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (bbdbfa6) to head (4e4f7b3).
Report is 30 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##              main     #1019   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          135       135           
  Lines         8950      9004   +54     
  Branches      2014      2019    +5     
=========================================
+ Hits          8950      9004   +54     

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[rmshaffer]

__repr__() is supposed to return a valid Python string which can be used to construct the object:

Suggested change

	f"ErfSquareWaveform('id': {self.id}, 'length': {self.length}, "
	f"'width': {self.width}, 'sigma': {self.sigma}, 'amplitude': {self.amplitude}, "
	f"'zero_at_edges': {self.zero_at_edges})"
	f"ErfSquareWaveform(id='{self.id}', length={self.length}, "
	f"width={self.width}, sigma={self.sigma}, amplitude={self.amplitude}, "
	f"zero_at_edges={self.zero_at_edges})"

but I see that existing classes in this file also have this problem. Are there unit tests that validate the output of these __repr__ functions?

[yitchen-tim]

The repr of all existing waveforms all use the the same convention. I will keep erf square the same for now.

[rmshaffer]

Couple of minor comments - feel free to defer them to a later PR if you'd like.