Summary:
Scope of the diff:
1. Middleware
`react-native-github/local-cli` and `react-native-internal-cli` uses a very similar set of middlewares (internal cli extends github version), so I decided to move it to a standalone file (middleware manager) in order to remove duplications and increase readability.
2. Types
Seems that after Flow upgrade to version 0.68 there were many type issues to resolve, so all of them were auto-mocked. This is fine, but I'd like to see Flow assists me with `Metro.createServer` -> `Metro.runServer` migration. Hence, I decided to resolve flow mocks, related to runServer.
3. `runServer` signature
In `react-native-github` repo I cleaned up `runServer` signature by removing `startCallback` and `readyCallback` from the function parameters and moved them to `runServer` instead.
4. Replace `createServer` by `runServer`
In `react-native-github` repo, `createServer` has been replaced by `runServer`. __Some of arguments are not mapped__.
Note that this diff will partially break argument mapping. This is intentional. @[100000044482482:ives] will fix it with a new config package.
Reviewed By: mjesun
Differential Revision: D8711717
fbshipit-source-id: a843ab576360ff7242099910d8f25a9cb0a388c0
c4a66a89a2