Combine impl CircuitData blocks

[mtreinish]

Summary

The CircuitData struct had two impl CircuitData blocks, one before the pymethods and the other after. While there is nothing wrong with doing this it is a bit confusing because the difference between the blocks is not clear. I expect this was caused by the size of the file and people missed that it already existed and we ended up with duplicates. This commit recombines the two blocks, opting to use the one after the pymethods as it was larger.

Details and comments

[qiskit-bot]

One or more of the following people are relevant to this code:

• @Qiskit/terra-core

[coveralls]

Pull Request Test Coverage Report for Build 11370831416

Details

• 247 of 256 (96.48%) changed or added relevant lines in 1 file are covered.
• 10 unchanged lines in 3 files lost coverage.
• Overall coverage increased (+0.003%) to 88.661%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
crates/circuit/src/circuit_data.rs	247	256	96.48%

Files with Coverage Reduction	New Missed Lines	%
crates/qasm2/src/expr.rs	1	94.02%
crates/qasm2/src/lex.rs	3	92.23%
crates/qasm2/src/parse.rs	6	97.15%

Totals
Change from base Build 11361871212:	0.003%
Covered Lines:	73188
Relevant Lines:	82548

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💛 - Coveralls

[raynelfss]

This makes sense to me, I assume the multiple impl were more contextual to group similar functions together. This just feels a bit more organized, so thank you for this 🚀