Add comprehensive tests for StreamingToolParser
Tests cover:
- Multiple tool calls in one response (single chunk and across chunks)
- Tool call followed by text (before, after, and both)
- Incomplete tool calls at various truncation points
- Parser reset behavior (buffer, incomplete state, unexecuted state)
- Buffer management and edge cases (streaming accumulation, empty chunks)
- JSON edge cases (escaped quotes, backslashes, nested braces)
- Tool call pattern variations (spacing, newlines)
- mark_tool_calls_consumed() functionality
- Duplicate tool call detection
- Multiple tool calls returned on stream finish
- has_message_like_keys validation
3a07a02b02