
This change adds `SessionError` and uses it in `SessionResult` and `LibraryResult` to report errors to callers. Constructors and factory method that used a simple `errorCode` to construct error variants of `SessionResult` and `LibraryResult` have been overloaded with a variant that uses a `SessionError` instead. While these methods and constructors are supposed to be deprecated, they aren't yet deprecated until the newly added alternative is stabilized. PiperOrigin-RevId: 642254336
Session test common module
Provides common components for use by session tests.