Reintroduce MAINTAIN privilege and pg_maintain predefined role.

Roles with MAINTAIN on a relation may run VACUUM, ANALYZE, REINDEX,
REFRESH MATERIALIZE VIEW, CLUSTER, and LOCK TABLE on the relation.
Roles with privileges of pg_maintain may run those same commands on
all relations.

This was previously committed for v16, but it was reverted in
commit 151c22deee due to concerns about search_path tricks that
could be used to escalate privileges to the table owner.  Commits
2af07e2f74, 59825d1639, and c7ea3f4229 resolved these concerns by
restricting search_path when running maintenance commands.

Bumps catversion.

Reviewed-by: Jeff Davis
Discussion: https://postgr.es/m/20240305161235.GA3478007%40nathanxps13

doc/src/sgml/ref/cluster.sgml

@@ -68,9 +68,8 @@ CLUSTER [ ( <replaceable class="parameter">option</replaceable> [, ...] ) ] [ <r
    <command>CLUSTER</command> without a
    <replaceable class="parameter">table_name</replaceable> reclusters all the
    previously-clustered tables in the current database that the calling user
-   owns, or all such tables if called by a superuser.  This
-   form of <command>CLUSTER</command> cannot be executed inside a transaction
-   block.
+   has privileges for.  This form of <command>CLUSTER</command> cannot be
+   executed inside a transaction block.
   </para>
 
   <para>
@@ -131,6 +130,11 @@ CLUSTER [ ( <replaceable class="parameter">option</replaceable> [, ...] ) ] [ <r
  <refsect1>
   <title>Notes</title>
 
+   <para>
+    To cluster a table, one must have the <literal>MAINTAIN</literal> privilege
+    on the table.
+   </para>
+
    <para>
     In cases where you are accessing single rows randomly
     within a table, the actual order of the data in the