Add a Backward Pass for the MetaOperators

Description

The metaOperator class was lacking an implementation for the backward pass. This MR address this.

The code is based on the implementation of the MetaOperator's forward pass.

Modified files : MetaOperator.cpp, MetaOperator.hpp

added Feature 🚀 StatusReview Ready labels

requested review from @pineapple and @cmoineau

assigned to @bhalimi

added 17 commits

• 67c1a0f5...c133d4a7 - 16 commits from branch dev
• f581de34 - add a backward pass for the metaoperators

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lgtm

approved this merge request

changed milestone to %aidge v0.6.0

added 19 commits

• f581de34...09583aa5 - 18 commits from branch dev
• e98f9c20 - add a backward pass for the metaoperators

Compare with previous version

enabled an automatic merge when all merge checks for e98f9c20 pass

approved this merge request

merged

mentioned in commit 5238c2bc