Add CLePAPS structural alphabet

[padix-key]

This PR adds support for the CLePAPS structural alphabet (https://doi.org/10.1142/s0219720008003461).

This PR is currently on hold as the obtained sequences do not fit the sequences from the reference implementation (taken from presentation slides as the original software is not available anymore). Curiously the centers of the clustered bending angles do not exceed 90°. Hence, I wonder if the centers given in the paper are correct

I found two misunderstandings between my code and the definitions in the paper. With these resolved and can reproduce almost all symbols from the reference sequences.

[codspeed-hq]

Merging this PR will degrade performance by 4.4%

⚡ 1 improved benchmark
❌ 2 (👁 2) regressed benchmarks
✅ 100 untouched benchmarks
⏩ 14 skipped benchmarks¹

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
⚡	benchmark_match_kmer_selection[BucketKmerTable(10000)-None]	353.8 µs	320.7 µs	+10.32%
👁	benchmark_match_kmer_selection[KmerTable-None]	246.3 µs	278.9 µs	-11.67%
👁	benchmark_match[KmerTable-None]	292.1 µs	325.8 µs	-10.34%

Tip

Curious why this is faster? Comment @codspeedbot explain why this is faster on this PR, or directly use the CodSpeed MCP with your agent.

---

_{Comparing padix-key:clepaps (82daff1) with main (b6127ed)}

Footnotes

1. 14 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩