* ATOM-15658 Better option of CreateCommonBuffer requires unique buffer name
- Change the CreateCommonBuffer function to not require an unique name by default.
- Remove the code for generating unique buffer names.
- Add buffer name to BufferAsset so it can be used for device object name instead of using asset file name.
- Change RPI::Buffer to use BufferName_AssetUuid as attachment id.
The crash was because the "BlendColorGradingLutImageAttachmentId" attachment got imported to attachment database twice.
This fix avoids import this attachment twice. It also avoid crash but only report a warning if an imported attachment wasn't used in any scope.
Enable both RHI and RPI validation (no visiable performance impact observed.