Add TYPEDB_DEV_MODE config to run local server in dev mode

[whummer]

Add TYPEDB_DEV_MODE=1 configuration variable to run local TypeDB server in dev mode.

For example, this allows to run a container manually locally (or alternatively, a DB server directly):

docker run --rm -it -p 1729:1729 -p 8000:8000 typedb/typedb

Please note: both port 1729 and 8000 need to be exposed by the TypeDB server locally in order to use TYPEDB_DEV_MODE.