add: config client-error-verbosity to set error verbosity

Set error verbosity using this config. The verbosity can
be set to `verbose` or `minimal` for client error responses.

This only affects client side HTTP responses, server side logs
are not affected by this config.

Signed-off-by: Taimoor Zaeem <taimoorzaeem@gmail.com>

test/io/configs/no-defaults-env.yaml

@@ -1,5 +1,6 @@
 PGRST_APP_SETTINGS_test2: test
 PGRST_APP_SETTINGS_test: test
+PGRST_CLIENT_ERROR_VERBOSITY: minimal
 PGRST_DB_AGGREGATES_ENABLED: true
 PGRST_DB_ANON_ROLE: root
 PGRST_DB_CHANNEL: postgrest