Refactor type generator

* Allows for generating top-level types for any embedded struct so
  that sub-types can be properly instantiated from calling code
  * Specifying `-no-embedded-types` will generate top-level types
    rather than embedding the struct

* Refactored "Device" API
  * All fields set to `omitempty` because it describes all possible
    device types, so effectively any field could be omitted any time
  * Fixed `get` call for "Device" API; replacing `rest` with `stat`

* Generated `get` and `update` calls for `Setting*` APIs

* Added `5.14.23` JSON files

fields/5.14.23/SettingRadioAi.json

@@ -0,0 +1,27 @@
+{
+  "enabled": "true|false",
+  "cron_expr": "",
+  "default": "true|false",
+  "radios": [
+    "na|ng"
+  ],
+  "optimize": [
+    "channel|power"
+  ],
+  "channels_ng": [
+    "1|2|3|4|5|6|7|8|9|10|11|12|13|14"
+  ],
+  "channels_na": [
+    "36|40|44|48|52|56|60|64|100|104|108|112|116|120|124|128|132|136|140|144|149|153|157|161|165"
+  ],
+  "ht_modes_ng": [
+    "^(20|40)$"
+  ],
+  "ht_modes_na": [
+    "^(20|40|80|160)$"
+  ],
+  "exclude_devices": [
+    "([0-9a-z]{2}:){5}[0-9a-z]{2}"
+  ],
+  "useXY": "true|false"
+}