This broke when we changed the way RTS stores version information. This
was never the right way to get the version in the `backup` command and
this PR fixes it, by getting the version from `info.json`.
Failure error:
```
Error: ENOENT: no such file or directory, open '/opt/appsmith/rts/version.js'
```
Move the files that are copied into the Docker image, into an `fs`
folder, that reflects the folder structure of that in the image. This
means two things right away:
1. A single `COPY` instruction in `Dockerfile` is enough to copy all the
files to their places.
2. The structure of files in the repo reflects that in the Docker image.
This makes working with the files/folders and troubleshooting with them
much easier.
❗ Note: **There's actually only 3 files changed, rest are just moved.**
