Embedding css and webfont dependencies allows the application to present
itself correctly in an environment that does not allow downloading the
files from a cdn.
Inspiration taken from #1492 but reworked to make use of embed.FS
simplifying the approach.
* Ensure sign-in page background is uniform throughout the page
Configured banners that take up large amounts of space leave a gap of blank
background between where the body ends and the footer starts. Fix this by
setting the style for the section containing the banner to match the body and
footer
* Add changelog entry
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Co-authored-by: Joel Speed <Joel.speed@hotmail.co.uk>