feat: Add support for jinja based template rendering of the dataset

[Abhishek-TAMU]

Description of the change

Added a handler apply_custom_data_formatting_jinja_template which does jinja based template rendering of the dataset.

Handling of edge case:
Example template:"### Input: {{Tweet text}} \n\n ### Response: {{text_label}}"
Jinja2 by default, does not support placeholders variable names with spaces (e.g., {{Tweet text}}), which will raise an error.

Hence additional preprocessing check (function: transform_placeholders) has been done. This checks if there is space between the placeholder variable and then process it accordingly (by modifying variable by {{element["Tweet text"]}}.

Related issue number

Issue: https://github.ibm.com/ai-foundation/watson-fm-stack-tracker/issues/1470

How to verify the PR

Verify added test cases.

Was the PR tested

• I have added >=1 unit test(s) for every new method I have added.
• I have ensured all unit tests pass

[github-actions]

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