Fix tool calls parsing for definitions containing arrays

[bwilliams2]

Description

Makes a small change to the parsing for tool_calls within Jinja templates. Previously square bracket pairs defined matching group which caused incomplete matching when square brackets were used within the tool_calls definition (e.g., arguments with arrays for function calls). This PR changes the matching logic to match the tool_call preamble definitions and removes then removes the matching preamble from the prompt. This avoids the need for more complex recursive bracket matching.

The bug was fixed in the two identical functions defined in promptflow-tools/promptflow/tools/common.py and promptflow-core/core/_prompty_utils.py. Test case added to promptflow-tools but I did not find existing test cases for the relevant code in promptflow-core. If directed to the right location, I can added additional test cases there.

Fixes #3388

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