Refactor campaign fields and paragraphs

[stephen-cox]

This has turned into a bit of a monster. It has turned into a complete refactor of the localgov_campaigns, localgov_campaigns_paragraphs and localgov_paragraph modules.

Work done includes:

• Renamed all paragraph types.
• Renamed all node and paragraph fields.
• Use media instead of files.
• Stripped out legacy and unneeded code and configuration.

This pull request closes: #7, #15, #25 and #26

Related pull requests: https://github.com/localgovdrupal/localgov_theme/pull/47, https://github.com/localgovdrupal/localgov_paragraphs/pull/5

To test all pull requests checkout the feature/campaigns-25-paragraphs-type branch on the project and run compose update --no-cache.

[stephen-cox]

Merging - we can create new issues if problems are found at sprint review tomorrow