pgxpool.Stat: Missing EmptyAcquireWaitTime()

[pquerna]

Is your feature request related to a problem? Please describe.

• EmptyAcquireWaitTime() is available in puddle since feat(pool): Add EmptyAcquireWaitTime stats puddle#34
• But it wasn't re-exposed in pgxpool.Stat{}

Describe the solution you'd like

• add an accessor function.

Additional context

• Related issue pgxpool: acquire wait time stats #1669

[vamshiaruru]

This would a pretty easy thing to add, right? Is someone adding it? I don't mind raising a PR for this as well.

[jackc]

I think it should be pretty easy - and no one is working on it as far as I know.

[vamshiaruru]

Created this PR: #2208