Fix Cosmetic "Dataset Explorer, after scrolling down a certain amount error"

[anthony-chaudhary]

Fixes
#1571

• This was a "Cosmetic" only item, since the '0' object was not a valid file there was nothing to unselect.
• The root of it injecting the '0' can be solved as part of refactoring the file push and concat block which should be seperate functions.

Additional Context

• Error: Cannot create property 'selected' on string '0'
• In theory a file object should never be a string '0', however, it seems to be adding this in, so until that root item is solved adding this check to filter out the '0's (which aren't valid file objects)
• In limited testing it only seems to happen once, so some process is adding it in a funny way
  For example:
  

[github-actions]

Unit Test Results

0 tests  ±0   0 ✔️ ±0   0s ⏱️ ±0s
0 suites ±0   0 💤 ±0 
0 files   ±0   0 ❌ ±0 

Results for commit b9c94eb. ± Comparison against base commit e2fb3ab.

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