closes: https://github.com/TryGhost/Ghost/issues/14973
- When fetching content using a non-standard charset, characters were notproperly decoded to utf-8 resulting in mangled text in the editor -> Detect charset and use iconv to decode the page text
- When requesting a non bookmark card, if no oembed data could be foundand we fallback to bookmark, a second network request to fetch the content was issued. This seemed unnecessary -> refactored to avoid that
refs https://github.com/TryGhost/Toolbox/issues/363
- the oembed service is completely standalone and could do with some
individual unit tests
- moving it out to a package allows us to draw the boundaries better and
allows us to remove some dependencies from the core package.json
