Fix code snippet deletion bug

[marthacryan]

Fixes #736. Adds a boolean to indicate that the cancel button was clicked on delete.

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[ajbozarth]

A suggested var rename but otherwise this LGTM. If I get time to test this locally before it's merged I'll update with an "approve"

[karlaspuldaro]

LGTM :)

[ajbozarth]

I've tested locally and it works great, once you address my previous comments (on readability and documentation) then this will be LGTM