tool-call: support Command R7B (+ return tool_plan "thoughts" in API) (#11585)

* `tool-call`: support Command R7B (w/ tool_plan return)

* `tool-call`: cleaner preservation of tokens + warn when likely bad chat template override

* `tool-call`: test cleanup / handle lazy grammar triggers

common/common.h

@@ -4,6 +4,7 @@
 
 #include "llama-cpp.h"
 
+#include <set>
 #include <string>
 #include <vector>
 #include <sstream>
@@ -163,6 +164,7 @@ struct common_params_sampling {
     bool                                grammar_lazy = false;
     std::vector<common_grammar_trigger> grammar_trigger_words;  // optional trigger words to trigger lazy grammar
     std::vector<llama_token>            grammar_trigger_tokens; // optional trigger tokens to trigger lazy grammar and print trigger special tokens.
+    std::set<llama_token>               preserved_tokens;
 
     std::vector<llama_logit_bias> logit_bias; // logit biases to apply
 
@@ -621,6 +623,7 @@ struct common_chat_msg {
     std::string role;
     std::string content;
     std::vector<common_tool_call> tool_calls;
+    std::string tool_plan = "";
 };
 
 // Check if the template supplied via "--chat-template" is supported or not. Returns true if it's valid