index-tool does not support collation

[dbonser]

DocumentDB 8.0 supports collation https://docs.aws.amazon.com/documentdb/latest/devguide/collation.html) but the index-tool flags any indexes with a collation document as unsupported.

For example, these indexes:

{
	"indexes":[
		{
			"v":2,
			"key":{
				"field1":1
			},
			"name":"field1_1_insensitive",
			"background":true,
			"collation":{
				"locale":"en_US",
				"caseLevel":false,
				"caseFirst":"off",
				"strength":1,
				"numericOrdering":false,
				"alternate":"non-ignorable",
				"maxVariable":"punct",
				"normalization":false,
				"backwards":false,
				"version":"57.1"
			},
			"ns":"database.collection"
		},
		{
			"v":2,
			"key":{
				"field2":1
			},
			"name":"field2_1_insensitive",
			"background":true,
			"collation":{
				"locale":"en_US",
				"caseLevel":false,
				"caseFirst":"off",
				"strength":1,
				"numericOrdering":false,
				"alternate":"non-ignorable",
				"maxVariable":"punct",
				"normalization":false,
				"backwards":false,
				"version":"57.1"
			},
			"ns":"database.collection"
		}
	]
}

are flagged as unsupported:

"database": {
	"collection": {
		"field1_1_insensitive": {
			"unsupported_index_options": [
				"collation"
			]
		},
		"field2_1_insensitive": {
			"unsupported_index_options": [
				"collation"
			]
		}
	}
}

Also, the version should be updated from 57.1 to 60.2 as per the second limitation at: https://docs.aws.amazon.com/documentdb/latest/devguide/collation.html#collation-limitations