GReader API add canonical information (#3391)
GReader API add canonical information (#3391)

For fluent-reader
#fix https://github.com/FreshRSS/FreshRSS/issues/3389
Better compatibility InoReader
https://www.inoreader.com/developers/stream-contents
Alkarex/FreshRSS,FreshRSS/FreshRSS,marienfressinaud/FreshRSS,aledeg/FreshRSS,aledeg/FreshRSS,FreshRSS/FreshRSS,Alkarex/FreshRSS,Alkarex/FreshRSS,marienfressinaud/FreshRSS,FreshRSS/FreshRSS,aledeg/FreshRSS,marienfressinaud/FreshRSS,marienfressinaud/FreshRSS,FreshRSS/FreshRSS,aledeg/FreshRSS,Alkarex/FreshRSS