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* add circular convolution

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* add type hint for __init__

* rounding off final values to 2 and minor changes

* add test case for unequal signals

* changes in list comprehension and enumeraton

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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>