feat(core_crypto): add glwe keyswitch

[Carl-Zama]

PR content/description

Add the GLWE keyswitch operation:

• Add the ability to decompose slices (i.e. polynomials)
• Add the ability to generate GLWE keyswitching keys
• Add some polynomial operations needed for GLWE keyswitch
• Add the GLWE keyswitch operation itself

Check-list:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)
• Relevant issues are marked as resolved/closed, related issues are linked in the description
• Check for breaking changes (including serialization changes) and add them to commit message following the conventional commit [specification][conventional-breaking]

[github-actions]

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[IceTDrinker]

Haven't read much yet but I don't see a glwe_keyswitch test file in algorithms/test

could we have one with parameters that have low pfail ?

[IceTDrinker]

@mayeul-zama I do believe this is available in TFHE-rs now right ?

[mayeul-zama]

Yes, added in #2084 (which is based on this PR)