model : add support for SmallThinker series (#14898)

model : add support for SmallThinker series (#14898)

* support smallthinker

* support 20b softmax, 4b no sliding window

* new build_moe_ffn_from_probs, and can run 4b

* fix 4b rope bug

* fix python type check

* remove is_moe judge

* remove set_dense_start_swa_pattern function and modify set_swa_pattern function

* trim trailing whitespace

* remove get_vocab_base of SmallThinkerModel in convert_hf_to_gguf.py

Co-authored-by: Sigbjørn Skjæret <redacted>
* better whitespace

Apply suggestions from code review

Co-authored-by: Sigbjørn Skjæret <redacted>
* use GGML_ASSERT for expert count validation

Co-authored-by: Sigbjørn Skjæret <redacted>
* Improve null pointer check for probs

Co-authored-by: Sigbjørn Skjæret <redacted>
* use template parameter for SWA attention logic

* better whitespace

Co-authored-by: Georgi Gerganov <redacted>
* move the creation of inp_out_ids before the layer loop

* remove redundant judge for probs

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Co-authored-by: Sigbjørn Skjæret <redacted>
Co-authored-by: Georgi Gerganov <redacted>