Fail-resistant catalog build

[charles-turner-1]

Is your feature request related to a problem? Please describe.

During the catalog builds for version 1.0.0, several build failures occurred due to broken datastores (Codex in particular - see #199) .

As the catalog is growing to include more datasets, it will be necessary to build & rebuild the catalog, without builds failing due to broken datastores.

This will likely

Describe the feature you'd like

• The build function in cli.py will need to be refactored to atomise the build, perhaps delegating each datastore build/translation to a separate function.
• Each of these delegated datastore builders/translators should be wrapped with some sort of error handling, which will
  1. Ensure catalog builds do not fail due to an individual (or many) broken datastores.
  2. Reports which datastores are broken.

Describe alternatives you've considered

Nil.

Additional context

#279