ShaderOptionStruct

[superkitcath]

[Migrated from JIRA ATOM-14466] Description:

Update AZSLc to support a ShaderOptionStruct concept to replace the various "COMMONOPTIONS" macros.

Details:

This like a namespace for shader options. All options across all structs will get flattened into a single options layout.

Acceptance Criteria:

• Replace all of the "COMMONOPTIONS" macros with a struct of some kind.

Additional Information:

[galibzon]

@santorac to decide if this is still needed.

[siliconvoodoo]

Hi, I could handle that if needed