[Drafts] Storage fixes (#9790)

* delete media from existsCache when deleting

* revoke media URLs

* skip revoking objecturls until the composer is completely closed

* [Drafts] Metrics (#9794)

* metrics for drafts

* Nit: format

* nit: use new util for clarity

* nit: use new util for clarity

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Co-authored-by: Eric Bailey <git@esb.lol>

---------

Co-authored-by: Eric Bailey <git@esb.lol>

src/analytics/metrics/types.ts

@@ -233,6 +233,53 @@ export type Events = {
     persist: boolean
     hasChanged: boolean
   }
+  'composer:open': {
+    logContext:
+      | 'Fab'
+      | 'PostReply'
+      | 'QuotePost'
+      | 'ProfileFeed'
+      | 'Deeplink'
+      | 'Other'
+    isReply: boolean
+    hasQuote: boolean
+    hasDraft: boolean
+  }
+  'draft:save': {
+    isNewDraft: boolean
+    hasText: boolean
+    hasImages: boolean
+    hasVideo: boolean
+    hasGif: boolean
+    hasQuote: boolean
+    hasLink: boolean
+    postCount: number
+    textLength: number
+  }
+  'draft:load': {
+    draftAgeMs: number
+    hasText: boolean
+    hasImages: boolean
+    hasVideo: boolean
+    hasGif: boolean
+    postCount: number
+  }
+  'draft:delete': {
+    logContext: 'DraftsList'
+    draftAgeMs: number
+  }
+  'draft:listOpen': {
+    draftCount: number
+  }
+  'draft:post': {
+    draftAgeMs: number
+    wasEdited: boolean
+  }
+  'draft:discard': {
+    logContext: 'ComposerClose' | 'BeforeDraftsList'
+    hadContent: boolean
+    textLength: number
+  }
 
   // Data events
   'account:create:begin': {}