This commit adds support for 4chan. This means that 4chan can be
selected as a new source type. When the 4chan source is selected a user
can select a board from which he wants to get the RSS feed.
This commit adds support to add Lemmy RSS feeds to FeedDeck. A user can
provide the url of an Lemmy instance, the url of a community or of an
user.
The special thing of the Lemmy source in opposite to the normal RSS
source is, that we parse the provided link form a feed item, to check if
it contains a image, video or YouTube url, to apply some special
formatting.
This commit adds a new source type "pinterest", which can be used to
follow the post of an user or a board on Pinterest. To use the new
source type a user can select the "Pinterest" item in the add source
modal. In the form a user can provide the username or board he wants to
follow via FeedDeck.
In the corresponding Supabase function we then convert the input
provided by the user to an valid RSS feed url for Pinterest. This means
that we have to add `/feed.rss` for users and `.rss` for boards to the
Pinterest url.
Then we generate the source and items as for the other sources and reuse
the existing components to render the preview and details item. We had
to adjust the rendering logic for these items, to ignore empty values,
from which also other sources will benefit.
Update the used Flutter version to 3.16.0 and all Flutter packages to
their latest version.
This commit also fixes all of the newly added analysis options and the
layout changes introduced with the new Flutter version (e.g. we have to
set the "tabAlignment" property in the "TabBar" widget).
Instead of rendering the images for a Nitter item within the description
in the details view, we are now rendering the images via the
"ItemMediaGallery" widget. To not render the images twice, we also added
the "disableImages" paramter to the "ItemDescription" widget, to not
render the images in the widget.
