API: Modify tool calling for wider compat

When revisiting tool calls, the formats have more or less become standard.
For greater compatibility with templates, primarily use the message.tools
parameter and remove the extra custom metadata that is no longer required.

However, unlike other backends, tabbyAPI still uses template metadata
to declare what the tool start string is. This allows for template-level
customization along with giving more power to the user while the server
exists to consume rather than work on a case-by-case basis.

Signed-off-by: kingbri <8082010+kingbri1@users.noreply.github.com>

endpoints/OAI/utils/tools.py

@@ -5,6 +5,31 @@ from typing import List
 from endpoints.OAI.types.tools import ToolCall
 
 
+TOOL_CALL_SCHEMA = {
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "type": "array",
+    "items": {
+        "type": "object",
+        "properties": {
+            "id": {"type": "string"},
+            "function": {
+                "type": "object",
+                "properties": {
+                    "name": {"type": "string"},
+                    "arguments": {
+                        # Converted to OAI's string in post process
+                        "type": "object"
+                    },
+                },
+                "required": ["name", "arguments"],
+            },
+            "type": {"type": "string", "enum": ["function"]},
+        },
+        "required": ["id", "function", "type"],
+    },
+}
+
+
 class ToolCallProcessor:
     @staticmethod
     def from_json(tool_calls_str: str) -> List[ToolCall]: