This PR builds console static assets into the server docker image at `/srv/console-assets`. When env var `HASURA_GRAPHQL_CONSOLE_ASSETS_DIR=/srv/console-assets` or flag `--console-assets-dir=/srv/console-assets` is set on the server, the files in this directory are served at `/console/assets/*`.
The console html template will have a variable called `cdnAssets: false` when this flag is set and it loads assets from server itself instead of CDN.
The assets are moved to a new bucket with a new naming scheme:
```
graphql-engine-cdn.hasura.io/console/assets/
/common/{}
/versioned/<version/{}
/channel/<channel>/<version>/{}
```
Console served by CLI will still load assets from CDN - will fix that in the next release.
* read version from env var at build time (close#1398)
* remove un-used imports, edit makefile
* edit makefile to add new targets and export variables
* only export VERSION in makefile
* read version by executing the script if env var is absent
* remove phase one/two distinction and hdbquery typeclass
* move extensions to default-extensions
* switch to LazyTx which only acquires a connection if needed
* move defns from TH module into Ops module
* remove tojson orphan instance for http exception
* remove orphan instance for dmlp1
* getTopLevelNodes will not throw any exceptions
