Model downloader dialog (#569)

* API core for model downloader

* initial basic dialog for missing models

* app.ts handling for missing models

* don't explode if getModels is a 404

* actually track downloads in progress

* overall pile of improvements to the missing models view

* minor fixes

* add setting to disable missing models warning

* temporarily remove 'models' entry from default graph

to avoid missing model dialog causing issues. Also because ckpt autodownloading shouldn't be allowed

* swap the url to a title

* add model directory to display

* match settingStore commit

* check setting before scanning models list

ie avoid redundant calcs when setting is disabled anyway

src/scripts/defaultGraph.ts

@@ -133,14 +133,5 @@ export const defaultGraph: ComfyWorkflowJSON = {
   groups: [],
   config: {},
   extra: {},
-  version: 0.4,
-  models: [
-    {
-      name: 'v1-5-pruned-emaonly.ckpt',
-      url: 'https://huggingface.co/runwayml/stable-diffusion-v1-5/resolve/main/v1-5-pruned-emaonly.ckpt',
-      hash: 'cc6cb27103417325ff94f52b7a5d2dde45a7515b25c255d8e396c90014281516',
-      hash_type: 'SHA256',
-      directory: 'checkpoints'
-    }
-  ]
+  version: 0.4
 }