🐛 Fix token file import of Figma generated file (#5591)

* 🐛 Fix token sets selection representation in exported theme

* 🐛 Fix the loss of token set order

* 🐛 Change data shape according to internal representaion

* 🐛 Persist sets order on import according to metadata

* 🐛 Add fallback for nil values

* 🐛 Fix test assertions accoding to the exported json format

* 🐛 Make `:is-source` optional

* ♻️ Fix test description

* ♻️ Remove outdated comment

common/test/common_tests/types/data/tokens-multi-set-example.json

@@ -802,7 +802,7 @@
     "description": null,
     "is-source": false,
     "modified-at": "2024-01-01T00:00:00.000+00:00",
-    "sets": [ "light" ]
+    "selectedTokenSets": {"light": "enabled"}
   } ],
   "$metadata": {
     "tokenSetOrder": ["core", "light", "dark", "theme"]

common/test/common_tests/types/tokens_lib_test.cljc

@@ -1163,7 +1163,8 @@
                                "is-source" false
                                "modified-at" now
                                "name" "theme-1"
-                               "sets" #{"core"}}]
+                               "selectedTokenSets" {"core" "enabled"}}]
+                   "$metadata" {"tokenSetOrder" ["core"]}
                    "core"
                    {"colors" {"red" {"600" {"$value" "#e53e3e"
                                             "$type" "color"}}}