## What changed?
<!-- Describe what has changed in this PR -->
Rename vars related to visibility.
## Why?
<!-- Tell your future self why have you made these changes -->
Ease to read code.
## How did you test it?
<!-- How have you verified this change? Tested locally? Added a unit
test? Checked in staging env? -->
Existing unit tests.
## Potential risks
<!-- Assuming the worst case, what can be broken when deploying this
change to production? -->
No.
## Documentation
<!-- Have you made sure this change doesn't falsify anything currently
stated in `docs/`? If significant
new behavior is added, have you described that in `docs/`? -->
## Is hotfix candidate?
<!-- Is this PR a hotfix candidate or does it require a notification to
be sent to the broader community? (Yes/No) -->
No
## What changed?
<!-- Describe what has changed in this PR -->
Remove support for standard visibility
## Why?
<!-- Tell your future self why have you made these changes -->
Standard visibility is deprecated.
## How did you test it?
<!-- How have you verified this change? Tested locally? Added a unit
test? Checked in staging env? -->
## Potential risks
<!-- Assuming the worst case, what can be broken when deploying this
change to production? -->
## Is hotfix candidate?
<!-- Is this PR a hotfix candidate or does it require a notification to
be sent to the broader community? (Yes/No) -->
<!-- Describe what has changed in this PR -->
**What changed?**
`Driver` interface (with two implementations) was added to the
postgresql persistence package in order to support other drivers than
`lib/pq`. Fixes https://github.com/temporalio/temporal/issues/1775
Essentially, this PR does
https://github.com/temporalio/temporal/pull/4914 in a
backward-compatible and extendable way
<!-- Tell your future self why have you made these changes -->
**Why?**
Since `lib/pq` does not support multi-node clusters
<!-- How have you verified this change? Tested locally? Added a unit
test? Checked in staging env? -->
**How did you test it?**
Existing tests
<!-- Assuming the worst case, what can be broken when deploying this
change to production? -->
**Potential risks**
No, since you should explicitly change the driver in your config file.
However, `connectAttributes` depend on the driver (e.g.,
`binary_parameters` is supported only by `lib/pq` and is not a part of
postresql standard), so one should be careful changing drivers in
production.
<!-- Is this PR a hotfix candidate or require that a notification be
sent to the broader community? (Yes/No) -->
**Is hotfix candidate?**
No
* Use serviceerror.Unavailable error type instead of serviceerror.Internal
* serviceerror.Unavailable indicates errors like service's dependency is down, retryable
* serviceerror.Internal indicates errors like NPE in service logic, non-retryable
* Try using a set of default database names when initializing admin connection
Aiven DB is a PostgreSQL compatible DB, but comes with a different default DB name
* Add version check method to SQL interface
* Remove tools version check method in favor of functions defined in persistence package
* Refactor tests to not depend on tools package
