Description

This PR makes optional copy/move constructors from other optionals to actuate only if the storage to copy from is engaged.
This prevents undefined behavior in the placement new when copying/moving data that is not initialized.
Specially, it tends to throw std::bad_array_new_length when trying to copy vectors.

@Mergifyio backport 2.2.x

Contributor Checklist

• Commit messages follow the project guidelines.
• The code follows the style guidelines of this project.
• Tests that thoroughly check the new feature have been added/Regression tests checking the bug and its fix have been added; the added tests pass locally
• Any new/modified methods have been properly documented using Doxygen.
• Changes are backport compatible: they do NOT break ABI nor change library core behavior.
• Changes are API compatible.
• N/A New feature has been added to the versions.md file (if applicable).
• Applicable backports have been included in the description.

Reviewer Checklist

• The PR has a milestone assigned.
• The title and description correctly express the PR's purpose.
• Check contributor checklist is correct.
• Check CI results: changes do not issue any warning.
• Check CI results: CI pass and failing tests are unrelated with the changes.

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This is an automatic backport of pull request #264 done by [Mergify](https://mergify.com).