feat!: add comprehensive Django support to inputs

[greatislander]

• I've read the guidelines for Contributing to the Platform Co-op Toolkit
• This isn't a duplicate of an existing pull request

Description

Adds support for alternative markup for all form inputs (based on Django conventions).

• Generic inputs (text, password, email, url, tel, number)
• Text areas
• Selects
• Checkboxes
• Custom checkboxes (with indeterminate state)
• Radio buttons

Steps to test

1. Visit deploy preview.
2. Test all form elements, as well as filter UI and dialog with input.

Expected behavior: Everything works and looks as expected.

Additional information

Nested checkboxes now require an .input--parent class on the parent checkbox. See: https://github.com/platform-coop-toolkit/pinecone/pull/376/files#diff-03a19b9935aa0f00880bc05b3fc94effR47

Related issues

• Resolves Pinecone lacks comprehensive support for Django form markup #369.
• Resolves Multi-select #370.

[netlify]

Deploy preview for pinecone ready!

Built with commit f5cae60

https://deploy-preview-376--pinecone.netlify.app

[jhung]

Functionally it's fine. I filed two new bugs I found in testing which can be addressed separately / later.

#378
#377