rename `quote icon`, move to properly authored namespace, updated reference and definitions to match

Fixes

Fixes #8

Description

The quote icon had unknown provenance as indicated in https://github.com/creativecommons/vocabulary/issues/8

It was safely assumed it was likely a font awesome icon since decorative icons mostly come from that library.

After further research it appears to be a custom creation by cc for cc. As a result its placement needs to be amended within the codebase.

https://github.com/creativecommons/vocabulary/issues/8#issuecomment-2075907634

The following changes were implemented:

the quote icon was moved from fa-icons.svg to cc-icons.svg
it was renamed from fa-quote to cc-quote
library-vars.css definitions were updated to match new namespace
references in vocabulary.css were updated to match new reference.
corrects an error in the markup of blog-post context specimen that was preventing the blockquote formatting from displaying properly
preview: https://deploy-preview-46--vocabulary-docs.netlify.app/specimen/contexts/blog-post.html (scroll down to blockqoute)

Screenshots

Checklist

[x] My pull request has a descriptive title (not a vague title like Update index.md).
[x] My pull request targets the default branch of the repository (main or master).
[x] My commit messages follow best practices.
[x] My code follows the established code style of the repository.
[ ] I added or updated tests for the changes I made (if applicable).
[ ] I added or updated documentation (if applicable).
[x] I tried running the project locally and verified that there are no visible errors.

Developer Certificate of Origin

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Developer Certificate of Origin

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creativecommons / vocabulary