v6: Mahoosive restructure

[nottrobin]

• Put API functions in a class object (Wordpress)
• Rewrite tests to use VCR and remove tests of internal functions
• Improve arguments to build_feed function
• Remove Django files
• Update build_blueprint arguments a bit
• Rename common_view_logic.py to views.py
• Rename logic.py to helpers.py

QA

I've implemented this in https://github.com/canonical-web-and-design/ubuntu.com/pull/7822, so follow the QA steps in that PR to test this module.

[jkfran]

We should update also the PR checks, like: https://github.com/canonical-web-and-design/canonicalwebteam.blog/blob/master/.github/workflows/tests.yml#L20

I am not sure why they are not running in this PR anyway.

[nottrobin]

This is WIP until I get around to creating a branch on ubuntu.com that makes use of this new version - until then it can't be QAed properly.