Enforce JSON formatting for schemas using CI checks

[aaronfranke]

I noticed that some of the schemas have minor inconsistencies between them. Some have "title":, and some have a space before the colon "title" :. Some files have "extensions": { },, some files have "extensions" : {},.

Sometimes arrays have spaces:

    "required": [ "sampler", "target" ]

Sometimes they do not:

    "required": ["packet"]

Sometimes files have a mix of tabs and spaces:

                    "output": "rotation",
		            "extensions" : {
		               "extension_name" : {
		                  "extension specific" : "value"
		               }
		            },
                    "extras" : {

While these inconsistencies could be fixed manually, I think it makes sense for Khronos to pick one JSON style and enforce it via a JSON formatter in CI checks so that it stays consistent. I would recommend applying this to vendor extensions too (it only changes the formatting of the JSON, not its contents, so I think it's fine).

Aside from JSON formatting, it would also be a good idea to enforce UTF-8 and enforce POSIX compliance by having end of line at end of file. Currently many files have this, and many files don't.