add if condition to visualize the kie output only when the output argument is supplied

[nabilragab]

Motivation

Improve the MMOCR package.

Modification

this prevents ImageFont OSError: unknown file format in production, when visualization is not required, as well as saves resources producing more efficient functionality to when required.

BC-breaking (Optional)

MINOR logical update

Use cases (Optional)

--output argument should be supplied to get the visualized KIE output

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