Fix exception and minor formatting issue in bedrock_agent_helper.py when tracing and formatting references

[rostcheck]

Amazon Bedrock Agent Samples Pull Request

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Describe your changes

• Concise description of the PR

Changes to bedrock_agent_helper.py to 1. fix an exception when tracing references (needed datetime custom formatter) and 2. fix minor reference formatting issue that sometimes clipped last character of description

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Issue ticket number and link

• Issue # (if applicable) (internal) V1679408150

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New Example Submissions:

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2. ...

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1. bedrock_agent_helper.py
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This tool is necessary because ...

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