support pg_catalog.pg_stat_get_numscans for dbeaver

[wangrunji0408]

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

Currently dbeaver can not show indexes in RisingWave. The following error will be given:

ERROR: Failed to prepare the statement

Caused by these errors (recent errors listed first):
  1: Failed to bind expression: pg_catalog.pg_stat_get_numscans(i.indexrelid)
  2: function pg_stat_get_numscans(integer) does not exist

To reproduce:

create table t(a int);
create index i on t(a);

Describe the solution you'd like

Implement this function.

Describe alternatives you've considered

No response

Additional context

Seems this function has been removed from documentation since pg 10.