recognize various test_* arg conventions (#1097)

test_data, test_deps, test_srcs, and test_tags are all commonly used conventions for rules. Buildifier should recognize these conventions and sort them; c.f. examples in [android](https://cs.github.com/JetBrains/android/blob/b373163869f676145341d60985cdbdaca3565c0b/project-system/BUILD#L9), [kythe](https://cs.github.com/cpehle/kythe/blob/ca97abf654f3ec7a099ff9ce93a0e041005b842d/kythe/go/serving/xrefs/BUILD#L6) [tensorflow](https://cs.github.com/418sec/tensorflow/blob/2fb5d641d852ff40df2dd85f461115ab9583d851/tensorflow/lite/testing/BUILD#L67), and other repos ([bbai](https://cs.github.com/rnburn/bbai-lib/blob/3a985793c34857ede615092e1efc7934d6d49a5b/example/median/BUILD#L17)

tables/tables.go

@@ -83,6 +83,9 @@ var IsLabelArg = map[string]bool{
 	"target_platforms":   true,
 	"template":           true,
 	"test":               true,
+	"test_data":          true,
+	"test_deps":          true,
+	"test_srcs":          true,
 	"tests":              true,
 	"tests_deps":         true,
 	"tool":               true,
@@ -142,6 +145,10 @@ var IsSortableListArg = map[string]bool{
 	"swigdeps":            true,
 	"swig_includes":       true,
 	"tags":                true,
+	"test_data":           true,
+	"test_deps":           true,
+	"test_srcs":           true,
+	"test_tags":           true,
 	"tests":               true,
 	"tools":               true,
 	"to_start_extensions": true,