vocab : add tokenizer support for jina-embeddings-v2-base-zh (#18756)

* vocab : add jina-embeddings-v2-base-zh (whitespace tokenizer)

* lowercase defaults to true

* type fix

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Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@scala.com>

gguf-py/gguf/constants.py

@@ -268,6 +268,8 @@ class Keys:
         CHAT_TEMPLATE        = "tokenizer.chat_template"
         CHAT_TEMPLATE_N      = "tokenizer.chat_template.{name}"
         CHAT_TEMPLATES       = "tokenizer.chat_templates"
+        # Normalizer constants
+        NORMALIZER_LOWERCASE = "tokenizer.ggml.normalizer.lowercase"
         # FIM/Infill special tokens constants
         FIM_PRE_ID           = "tokenizer.ggml.fim_pre_token_id"
         FIM_SUF_ID           = "tokenizer.ggml.fim_suf_token_id"