No need for a loop of String conversions with String comparisons, which are much slower.

Before (#135 implementation):

• Detect if icon path starts with uid://
• Open UID cache and get each entry
• Convert the entry's id to text (slow)
• Compare to icon path (string comparison, slow)
• Once the corresponding UID is found, give it to icon_path

After

• Detect if icon path starts with uid://
• Convert the icon path UID to an integer just once
• Check if the UID is valid. If not, skip the last steps entirely.
• Open UID cache and get each entry
• Compare the entry id to the icon id (integer comparison, fast)
• Once the corresponding UID is found, give it to icon_path

Like I mentioned in #135, I did the same procedure done in Godot itself, but turns out it had this tiny overhead. I submitted this change there too.

Of course, this has been tested before submitting.