Support additional block types

[Morsey187]

Add additonal blocks missing from the designs (you may need access to view).

    # additonal blocks to add to SectionBlocks
    image = ImageBlock()
    quote = QuoteBlock()
    accordion = AccordionBlock()   
    featured_article = FeaturedArticleBlock()
    cards = CardSectionBlock()
    plain_cards = PlainCardSectionBlock()

    # additonal field to add to NewsListingPage
    featured_card = StreamField(
         [("cta", FeaturedArticleBlock())],
         blank=True,
         max_num=1,
         help_text="Choose a featured article to display at the very top of the list.",   
    )

Will require adding templates and CSS, potentially javascript for accordions.

[jsma]

Noting here that the AccordionBlock name is reused for both the container block as well as the list items it contains:

https://github.com/torchbox/wagtail-news-template/blob/9a4defdb95e06ab4dff464b80d320b9b83bb2191/project_name/utils/blocks.py#L14-L29

Perhaps the first should be renamed e.g., AccordionBlockItem?