fix (icon label): return false for isEligible if there is no icon block

[kaeizen]

if icon label is modified and does not have icon block, isEligible returns an error.

This fix checks if the icon label's inner block contains icon block.

[github-actions]

🤖 Pull request artifacts

file	commit
pr3368-stackable-3368-merge.zip	2c00470

[github-actions]

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