Implement ideas from T96297:
- Fix "invalid axis settings" (both forward & up along the same
direction) validation: now similar to the Python based code, when
invalid axis is applied, the other axis is changed to not conflict.
- Make axis enums be expanded inside the row, similar to Collada UI.
- Move "selected only" near the top, similar to how it's in Collada,
USD, FBX and glTF export UIs.
- Move animation export options to the bottom.
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