initial model store (#674)

* initial model store

* refactor the 'modelstoreserviceimpl' to pinia

* pepper in some reactive

the inner ModelStore (per-folder) can't be pinia because its made of temporary instances, but it can be reactive

* use refs in metadata class

* remove 'reactive'

* remove ref too

* add simple unit tests for modelStore

* make things worse via autoformatting

* move mock impls to a function

src/scripts/api.ts

@@ -343,6 +343,19 @@ class ComfyApi extends EventTarget {
     return await res.json()
   }
 
+  /**
+   * Gets the metadata for a model
+   * @param {string} folder The folder containing the model
+   * @param {string} model The model to get metadata for
+   * @returns The metadata for the model
+   */
+  async viewMetadata(folder: string, model: string) {
+    const res = await this.fetchApi(
+      `/view_metadata/${folder}?filename=${encodeURIComponent(model)}`
+    )
+    return await res.json()
+  }
+
   /**
    * Tells the server to download a model from the specified URL to the specified directory and filename
    * @param {string} url The URL to download the model from