Force index for task history requests by host and start/update times

[fabatef]

Forces task history search queries to use the hostUpadtedAt index for requests that only specify host and startedAt/updatedAt fields. These queries currently timeout intermittently since the hostUpdatedAt index isn't consistently chosen by the optimizer.

[ssalinas]

Mentioned this to @baconmania , but documenting here as well. If we are adding something non-postgres-compatible, we should make this into an abstract method instead. It can be implemented only in the mysql version and essentially a no-op on the postgres side

[ssalinas]

@baconmania will let you review here

[ssalinas]

@fabatef can we get the merge conflicts resolved here at some point. Realized this one never actually made it through to stable

[ssalinas]

🚢