Update PQparameterStatus and ParameterStatus docs

Cover scram_iterations, which was added in commit b577743.  While
at it, turn the list into a <simplelist> with 2 columns, which is much
nicer to read.

In master, remove mentions of antediluvian versions before which some
parameters were not reported.

Noticed while investigating a question by Maiquel Grassi.

Backpatch to 16.

Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Jelte Fennema-Nio <postgres@jeltef.nl>
Discussion: https://postgr.es/m/202401301236.mc5ebrohhtsd@alvherre.pgsql

Author: alvherre

doc/src/sgml/libpq.sgml

@@ -2509,20 +2509,23 @@ const char *PQparameterStatus(const PGconn *conn, const char *paramName);
       </para>
 
       <para>
-       Parameters reported as of the current release include
-       <varname>server_version</varname>,
-       <varname>server_encoding</varname>,
-       <varname>client_encoding</varname>,
-       <varname>application_name</varname>,
-       <varname>default_transaction_read_only</varname>,
-       <varname>in_hot_standby</varname>,
-       <varname>is_superuser</varname>,
-       <varname>session_authorization</varname>,
-       <varname>DateStyle</varname>,
-       <varname>IntervalStyle</varname>,
-       <varname>TimeZone</varname>,
-       <varname>integer_datetimes</varname>, and
-       <varname>standard_conforming_strings</varname>.
+       Parameters reported as of the current release include:
+       <simplelist type="vert" columns="2">
+        <member><varname>application_name</varname></member>
+        <member><varname>client_encoding</varname></member>
+        <member><varname>DateStyle</varname></member>
+        <member><varname>default_transaction_read_only</varname></member>
+        <member><varname>in_hot_standby</varname></member>
+        <member><varname>integer_datetimes</varname></member>
+        <member><varname>IntervalStyle</varname></member>
+        <member><varname>is_superuser</varname></member>
+        <member><varname>scram_iterations</varname></member>
+        <member><varname>server_encoding</varname></member>
+        <member><varname>server_version</varname></member>
+        <member><varname>session_authorization</varname></member>
+        <member><varname>standard_conforming_strings</varname></member>
+        <member><varname>TimeZone</varname></member>
+       </simplelist>
        (<varname>server_encoding</varname>, <varname>TimeZone</varname>, and
        <varname>integer_datetimes</varname> were not reported by releases before 8.0;
        <varname>standard_conforming_strings</varname> was not reported by releases
@@ -2532,7 +2535,8 @@ const char *PQparameterStatus(const PGconn *conn, const char *paramName);
        9.0;
        <varname>default_transaction_read_only</varname> and
        <varname>in_hot_standby</varname> were not reported by releases before
-       14.)
+       14; <varname>scram_iterations</varname> was not reported by releases
+       before 16.)
        Note that
        <varname>server_version</varname>,
        <varname>server_encoding</varname> and

doc/src/sgml/protocol.sgml

@@ -1314,20 +1314,23 @@ SELCT 1/0;<!-- this typo is intentional -->
 
    <para>
     At present there is a hard-wired set of parameters for which
-    ParameterStatus will be generated: they are
-    <varname>server_version</varname>,
-    <varname>server_encoding</varname>,
-    <varname>client_encoding</varname>,
-    <varname>application_name</varname>,
-    <varname>default_transaction_read_only</varname>,
-    <varname>in_hot_standby</varname>,
-    <varname>is_superuser</varname>,
-    <varname>session_authorization</varname>,
-    <varname>DateStyle</varname>,
-    <varname>IntervalStyle</varname>,
-    <varname>TimeZone</varname>,
-    <varname>integer_datetimes</varname>, and
-    <varname>standard_conforming_strings</varname>.
+    ParameterStatus will be generated.  They are:
+    <simplelist type="vert" columns="2">
+     <member><varname>application_name</varname></member>
+     <member><varname>client_encoding</varname></member>
+     <member><varname>DateStyle</varname></member>
+     <member><varname>default_transaction_read_only</varname></member>
+     <member><varname>in_hot_standby</varname></member>
+     <member><varname>integer_datetimes</varname></member>
+     <member><varname>IntervalStyle</varname></member>
+     <member><varname>is_superuser</varname></member>
+     <member><varname>scram_iterations</varname></member>
+     <member><varname>server_encoding</varname></member>
+     <member><varname>server_version</varname></member>
+     <member><varname>session_authorization</varname></member>
+     <member><varname>standard_conforming_strings</varname></member>
+     <member><varname>TimeZone</varname></member>
+    </simplelist>
     (<varname>server_encoding</varname>, <varname>TimeZone</varname>, and
     <varname>integer_datetimes</varname> were not reported by releases before 8.0;
     <varname>standard_conforming_strings</varname> was not reported by releases
@@ -1337,7 +1340,8 @@ SELCT 1/0;<!-- this typo is intentional -->
     9.0;
     <varname>default_transaction_read_only</varname> and
     <varname>in_hot_standby</varname> were not reported by releases before
-    14.)
+    14; <varname>scram_iterations</varname> was not reported by releases
+    before 16.)
     Note that
     <varname>server_version</varname>,
     <varname>server_encoding</varname> and