TemporalTables: consider FromSql overloads that can take temporal information (AsOf only)

[maumar]

Both TemporalAsOf and FromSql* require DbSet as source so there is no way to specify temporal information for entity produced using FromSql. If someone creates temporal query inside FromSql, temporal information won't be propagated into other navigations that are included etc on top of it.

We can provide overload that will allow specifying the AsOf information (only one that makes sense, since nav expnasion doesn't work for any other temporal operation), so that we can do the propagation correctly

[ajcvickers]

See also discussion in #14525