refactor: Replace interpolatedstring-perl6 with neat-interpolation

The former depends on th-orphans which does not cross-compile well,
because of template haskell usage.

neat-interpolation is also much better maintained.

This also potentially helps with packaging for Debian/Ubuntu in #2273.

src/PostgREST/Config/Database.hs

@@ -24,7 +24,7 @@ import qualified Hasql.Statement            as SQL
 import qualified Hasql.Transaction          as SQL
 import qualified Hasql.Transaction.Sessions as SQL
 
-import Text.InterpolatedString.Perl6 (q, qc)
+import NeatInterpolation (trimming)
 
 import Protolude
 
@@ -95,7 +95,7 @@ queryDbSettings preConfFunc prepared =
   let transaction = if prepared then SQL.transaction else SQL.unpreparedTransaction in
   transaction SQL.ReadCommitted SQL.Read $ SQL.statement dbSettingsNames $ SQL.Statement sql (arrayParam HE.text) decodeSettings prepared
   where
-    sql = [qc|
+    sql = encodeUtf8 [trimming|
       WITH
       role_setting AS (
         SELECT setdatabase as database,
@@ -109,25 +109,25 @@ queryDbSettings preConfFunc prepared =
                substr(setting, 1, strpos(setting, '=') - 1) as k,
                substr(setting, strpos(setting, '=') + 1) as v
         FROM role_setting
-        {preConfigF}
+        ${preConfigF}
       )
       SELECT DISTINCT ON (key)
-             replace(k, '{prefix}', '') AS key,
+             replace(k, '${prefix}', '') AS key,
              v AS value
       FROM kv_settings
-      WHERE k = ANY($1) AND v IS NOT NULL
+      WHERE k = ANY($$1) AND v IS NOT NULL
       ORDER BY key, database DESC NULLS LAST;
     |]
     preConfigF = case preConfFunc of
       Nothing   -> mempty
-      Just func -> [qc|
+      Just func -> [trimming|
           UNION
           SELECT
             null as database,
             x as k,
             current_setting(x, true) as v
-          FROM unnest($1) x
-          JOIN {func}() _ ON TRUE
+          FROM unnest($$1) x
+          JOIN ${func}() _ ON TRUE
       |]::Text
     decodeSettings = HD.rowList $ (,) <$> column HD.text <*> column HD.text
 
@@ -136,7 +136,7 @@ queryRoleSettings pgVer prepared =
   let transaction = if prepared then SQL.transaction else SQL.unpreparedTransaction in
   transaction SQL.ReadCommitted SQL.Read $ SQL.statement mempty $ SQL.Statement sql HE.noParams (processRows <$> rows) prepared
   where
-    sql = [q|
+    sql = encodeUtf8 [trimming|
       with
       role_setting as (
         select r.rolname, unnest(r.rolconfig) as setting
@@ -161,14 +161,15 @@ queryRoleSettings pgVer prepared =
         i.value as iso_lvl,
         coalesce(array_agg(row(kv.key, kv.value)) filter (where key <> 'default_transaction_isolation'), '{}') as role_settings
       from kv_settings kv
-      join pg_settings ps on ps.name = kv.key |] <>
-      (if pgVer >= pgVersion150
-        then "and (ps.context = 'user' or has_parameter_privilege(current_user::regrole::oid, ps.name, 'set')) "
-        else "and ps.context = 'user' ") <> [q|
+      join pg_settings ps on ps.name = kv.key and (ps.context = 'user' ${hasParameterPrivilege})
       left join iso_setting i on i.rolname = kv.rolname
       group by kv.rolname, i.value;
     |]
 
+    hasParameterPrivilege
+      | pgVer >= pgVersion150 = "or has_parameter_privilege(current_user::regrole::oid, ps.name, 'set')"
+      | otherwise             = ""
+
     processRows :: [(Text, Maybe Text, [(Text, Text)])] -> (RoleSettings, RoleIsolationLvl)
     processRows rs =
       let