Quadrature methods for circuit components and states

[elib20]

Context: We would like convenience methods for evaluating the quadrature basis representation of circuit components and states.

Description of the Change:

• renames the quadrature method for circuit components to quadrature_triple
• adds a new to_quadrature method to convert to the quadrature representation from Bargmann
• adds a new quadrature method for circuit components to evaluate the quadrature basis function over an array of points. This works for Bargmann and Fock representations, batched or unbatched.
• adds a new quadrature_distribution method for Ket and DM to evaluate the quadrature basis probability distribution over an array of points. This works for Bargmann and Fock representations, batched or unbatched.

Benefits:

• Convenient methods for users
• Quadrature methods now work for Fock representation

Possible Drawbacks: None

Related GitHub Issues:

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 98.41270% with 1 line in your changes missing coverage. Please review.

Project coverage is 89.52%. Comparing base (92e42e3) to head (bc4c44c). Report is 1 commits behind head on develop.

Files with missing lines	Patch %	Lines
mrmustard/lab_dev/circuit_components.py	95.45%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #443 +/- ## =========================================== + Coverage 89.47% 89.52% +0.04% =========================================== Files 102 102 Lines 7365 7408 +43 =========================================== + Hits 6590 6632 +42 - Misses 775 776 +1 ``` | [Files with missing lines](https://app.codecov.io/gh/XanaduAI/MrMustard/pull/443?dropdown=coverage&src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=XanaduAI) | Coverage Δ | | |---|---|---| | [mrmustard/lab\_dev/states/base.py](https://app.codecov.io/gh/XanaduAI/MrMustard/pull/443?src=pr&el=tree&filepath=mrmustard%2Flab_dev%2Fstates%2Fbase.py&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=XanaduAI#diff-bXJtdXN0YXJkL2xhYl9kZXYvc3RhdGVzL2Jhc2UucHk=) | `96.26% <100.00%> (+0.13%)` | :arrow_up: | | [mrmustard/physics/fock.py](https://app.codecov.io/gh/XanaduAI/MrMustard/pull/443?src=pr&el=tree&filepath=mrmustard%2Fphysics%2Ffock.py&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=XanaduAI#diff-bXJtdXN0YXJkL3BoeXNpY3MvZm9jay5weQ==) | `92.94% <100.00%> (+0.38%)` | :arrow_up: | | [mrmustard/lab\_dev/circuit\_components.py](https://app.codecov.io/gh/XanaduAI/MrMustard/pull/443?src=pr&el=tree&filepath=mrmustard%2Flab_dev%2Fcircuit_components.py&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=XanaduAI#diff-bXJtdXN0YXJkL2xhYl9kZXYvY2lyY3VpdF9jb21wb25lbnRzLnB5) | `99.08% <95.45%> (-0.28%)` | :arrow_down: | ------ [Continue to review full report in Codecov by Sentry](https://app.codecov.io/gh/XanaduAI/MrMustard/pull/443?dropdown=coverage&src=pr&el=continue&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=XanaduAI). > **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=XanaduAI) > `Δ = absolute (impact)`, `ø = not affected`, `? = missing data` > Powered by [Codecov](https://app.codecov.io/gh/XanaduAI/MrMustard/pull/443?dropdown=coverage&src=pr&el=footer&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=XanaduAI). Last update [92e42e3...bc4c44c](https://app.codecov.io/gh/XanaduAI/MrMustard/pull/443?dropdown=coverage&src=pr&el=lastupdated&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=XanaduAI). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=XanaduAI).

[ziofil]

Maybe it's late for this suggestions, but wouldn't it be sufficient to apply BtoQ on all wires and return the ansatz? Then the ansatz itself can be called independently.

[ziofil]

I approved it, but make sure those indices are in the right order