* Fix Bangumi tracking losing track of login state
kotlinx.serialization does NOT serialize default values (like
createdAt in BGMOAuth.kt), so every time the Bangumi tracker
deserialized the tracker OAuth, createdAt was set to the time of the
read, not the time of issuance.
Separately, BangumiInterceptor did correctly fetch new OAuth
credentials upon detected expiry of the stored credentials and saved
them, but did not use them for the current request (the new
credentials were used for all subsequent requests only). This led to
401 errors from Bangumi because the expired access_token was provided.
A subsequent request using the newly acquired access_token would end
up being successful.
* Add CHANGELOG.md entry
(cherry picked from commit dce6aacf02d07f3f123b19b1b74cbbe18c28852b)
# Conflicts:
# CHANGELOG.md
1fa05703fa