Fixed file explorer - Mostly error handling

[Dyst0rti0n]

The Refresh() method in the file explorer model could lead to a nil pointer dereference with different flaws:

• Ignored the error from filetree.CreateTree()
• Used flawed logic to re-select a node, which could result
  in an index of -1.

[NucleoFusion]

I came across another error yesterday in file explorer, a user should not be allowed to delete the root folder. While he is allowed rn i beleive.
All in all looks pretty good, and I'll get on it in a while.

[Dyst0rti0n]

I came across another error yesterday in file explorer, a user should not be allowed to delete the root folder. While he is allowed rn i beleive. All in all looks pretty good, and I'll get on it in a while.

AH yes that would occur actually, nice spot. Going to do a bit more tonight and get more understanding into the code. Very nice build thus far I might say. Great project and it's wrote in the holy grail - Go

[NucleoFusion]

Thank! Means a lot
Tbh it's my first big project anywhere that has gained traction, and I was unsure if I did it correctly.