feat(oas3): Show file upload for schema binary format (#7325)

* fix(ux): display actual content type instead of hard-coded application/octet-stream

* feat(ux): show file upload when schema has "format: binary", fixes #5636

* feat(ux): show file upload when schema has "format: base64"

According to
https://github.com/swagger-api/swagger-ui/pull/7325#issuecomment-861684260
the uploaded file should be converted to base64 automatically.

* feat(ux): add cypress tests for displaying an upload button

src/core/plugins/oas3/components/request-body.jsx

@@ -107,18 +107,22 @@ const RequestBody = ({
   }
 
   const isObjectContent = mediaTypeValue.getIn(["schema", "type"]) === "object"
+  const isBinaryFormat = mediaTypeValue.getIn(["schema", "format"]) === "binary"
+  const isBase64Format = mediaTypeValue.getIn(["schema", "format"]) === "base64"
 
   if(
     contentType === "application/octet-stream"
     || contentType.indexOf("image/") === 0
     || contentType.indexOf("audio/") === 0
     || contentType.indexOf("video/") === 0
+    || isBinaryFormat
+    || isBase64Format
   ) {
     const Input = getComponent("Input")
 
     if(!isExecute) {
       return <i>
-        Example values are not available for <code>application/octet-stream</code> media types.
+        Example values are not available for <code>{contentType}</code> media types.
       </i>
     }
 
@@ -163,7 +167,7 @@ const RequestBody = ({
                 || prop.hasIn(["items", "default"])
               const useInitialValFromEnum = prop.has("enum") && (prop.get("enum").size === 1 || required)
               const useInitialValue = useInitialValFromSchemaSamples || useInitialValFromEnum
-              
+
               let initialValue = ""
               if (type === "array" && !useInitialValue) {
                 initialValue = []