Fix/TopK converter 1D input support

[dongwoonhyun]

Description

TopK's converter requires inputs to be at least 2D. This PR extends support to 1D inputs using unsqueeze -> topk -> squeeze. A regression test is also added.

Type of change

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• My code follows the style guidelines of this project (You can use the linters)
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas and hacks
• I have made corresponding changes to the documentation
• I have added tests to verify my fix or my feature
• New and existing unit tests pass locally with my changes
• I have added the relevant labels to my PR in so that relevant reviewers are notified

[SrivastavaKshitij]

@narendasan @apbose : for viz