It used to be that this was only enabled with log-level=debug.
But the default log-level is misleading, for example:
```
$ PGRST_DB_SCHEMAS="apflora" postgrest-with-postgresql-16 -f test/io/big_schema.sql postgrest-run
...
13/Nov/2024:22:08:20 -0500: Config reloaded
13/Nov/2024:22:08:20 -0500: Schema cache queried in 36.3 milliseconds
13/Nov/2024:22:08:20 -0500: Schema cache loaded 326 Relations, 305 Relationships, 7 Functions, 0 Domain Representations, 4 Media Type Handlers, 1194 Timezones
```
The "Schema cache loaded" can take a while to appear, yet the 22:08:20
time is the same. If we reveal the load time this is clarified:
```
13/Nov/2024:22:08:37 -0500: Schema cache loaded in 16770.1 milliseconds
```
Fixes https://github.com/PostgREST/postgrest/issues/3523.
Now if there's a failure when obtaining the pg version OR schema cache,
we do the same retrying process. This way we don't add two retries.
Refactors and renames the "connectionWorker" to "schemaCacheLoader".
This makes more sense since what we really want is the schema cache,
the version is the pre-requisite for ensuring our
schema cache queries work.
Additionally, we no longer log ` Attempting to connect to the database...`
at startup unnecessarily. This is only logged whenever there's a retry attempt.
The schema cache and OpenAPI output would currently list the first found
enum with the same name instead of the correct type. One other case
where this comes up is when a regular type and an enum type have the
same name. For example in the spec fixtures, we have an enum called
"bit". Every "bit" type, no matter whether it's that enum or the
built-in bit type, will show those enum options in the OpenApi output.
Not adding a test, because OpenAPI is supposed to go away in the future
anyway.
Update hasql-notifications to include the fix on
https://github.com/diogob/hasql-notifications/issues/24.
Which now reveals the following error:
```
$ postgrest-with-postgresql-16 --replica -f test/spec/fixtures/load.sql postgrest-run
17/May/2024:18:35:38 -0500: Successfully connected to PostgreSQL 16.2 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 13.2.0, 64-bit
17/May/2024:18:35:38 -0500: Could not listen for notifications on the "pgrst" channel. ERROR: cannot execute LISTEN during recovery
17/May/2024:18:35:38 -0500: Retrying listening for notifications...
```
This is still not good because the LISTEN channel will be retried
forever without a backoff.
