RDISCROWD-5653 Bug With Showing Completed Answers

[XiChenn]

Issue number of the reported bug or feature request: RDISCROWD-5653

Describe your changes

• Using document.getElementById("annex-viewer") or document.getElementById("shell-container") to identify Annex shell instead of shell.setAttribute("hash", "anything"); because Annex doesn't always have to set hash attribute.
• For "table-element", if the existing data contains a list of javascript object and task.info.some_attribute in the object, the code will parse the ``task.info.some_attribute``` and get the corresponding data for it.
• Exception handling added.

Testing performed
Tested locally.

Additional context
None

[coveralls]

Pull Request Test Coverage Report for Build 4118751335

• 17 of 17 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.005%) to 93.99%

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Totals
Change from base Build 4076129468:	0.005%
Covered Lines:	16516
Relevant Lines:	17572

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💛 - Coveralls

[n00rsy]

lgtm