* [WiP] improve load_examples
related to #7472, longer term we will generate the examples by exporting
them into tarball as in #7472. In the meantime, we need this subset of
the features:
* allowing specifying an alternate database connection for examples
* allowing a --only-metadata flag to `load_examples` to load only
dashboard and chart definitions, no actual data is loaded
* Improve logging
* Rename data->examples
* Load only if not exist
* By default do not load, add a force flag
* fix build
* set published to true
* [utils] gathering/refactoring into a "utils/" folder
Moving current utils.py into utils/core.py and moving other *util*
modules under this new "utils/" as well.
Following steps include eroding at "utils/core.py" and breaking it down
into smaller modules.
* Improve tests
* Make loading examples in scope for tests
* Remove test class attrs examples_loaded and requires_examples
Daniel Vaz Gaspar
Marcus
John Bodley
Maxime Beauchemin
timifasubaa
michellethomas
fabianmenges