Move cyclic repetition code to earlier pipeline instead of in emitter

[ZenithalHourlyRate]

Subissue for #1191.

Currently for heir-simd-vectorizer/tensor_ext::rotate to work (i.e. HECO-style optimization like rotate-and-reduce), we assumed a cyclic repetition packing in the ciphertext slot (also assumes the plaintext slot num divides ct slot num).

However, this is handled in emitter (i.e. #1129 and #1226), the very last stage. As this is enforced by the heir-simd-vectorizer, it is clearly error-prone when we handle the assumption in two places (early pipeline and emitter).

[github-actions]

This issue has 1 outstanding TODOs:

• lib/Target/Lattigo/LattigoEmitter.cpp:276: move cyclic repetition to earlier pipeline

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