Update demo data hook to copy media files (#3441)

* Simplify settings.py / config.py

- get_setting function has been streamlined
- move some functions into config.py

* Spelling fix: IGNORRED is IGNORED

* Ensure yaml is installed as part of docker image

- invoke path is still mucking us around

* Fix broken migration

* Copy media files from demo dataset when installing test data

* Cleanup settings.py

* Fix for configuration file traversal

* Line fix

* Update quickstart guide for docker

* Allow plugin file and plugin dir to be specified in configuration file

* Cleanup config template file

* Allow secret_key information to be provided in configuration file

* Adjust root paths for CI tests

* resolve paths

* Revert paths for CI step

* remove dead code

* Revert configuration variables to old names

- Prevent breaking changes

* Simplify secret key generation

* Fix default timeout for background worker process

* Revert change for customization options

.gitignore

@@ -50,7 +50,6 @@ docs/_build
 inventree_media
 inventree_static
 static_i18n
-inventree-data
 
 # Local config file
 config.yaml
@@ -79,6 +78,8 @@ js_tmp/
 
 # Development files
 dev/
+data/
+env/
 
 # Locale stats file
 locale_stats.json