[Video] Add uploaded video to post (#4884)

* video uploads!

* use video upload lexicons

* add missing postgate

* remove references to prerelease package

* fix scrubber showing a "0"

* Delete types.ts

* rm logs

* rm upload header

---------

Co-authored-by: Samuel Newman <10959775+mozzius@users.noreply.github.com>

src/state/queries/video/util.ts

@@ -1,3 +1,6 @@
+import {useMemo} from 'react'
+import {AtpAgent} from '@atproto/api'
+
 const UPLOAD_ENDPOINT = process.env.EXPO_PUBLIC_VIDEO_ROOT_ENDPOINT ?? ''
 
 export const createVideoEndpointUrl = (
@@ -13,3 +16,11 @@ export const createVideoEndpointUrl = (
   }
   return url.href
 }
+
+export function useVideoAgent() {
+  return useMemo(() => {
+    return new AtpAgent({
+      service: UPLOAD_ENDPOINT,
+    })
+  }, [])
+}