nix(loadtest): move errors into mixed

Because we separate loadtest results per URL now, we can move the error
tests into the regular mixed bag of loadtests - we will be able to tell
from the misspelled URLs when we hit a regression in that area.

We should be able to do similar things for JWT tests, but we'll need
more infrastructure here.

test/load/fixtures.sql

@@ -49,3 +49,9 @@ REVOKE ALL PRIVILEGES ON TABLE
 FROM postgrest_test_anonymous;
 
 GRANT ALL ON TABLE authors_only TO postgrest_test_author;
+
+SELECT format('CREATE TABLE test.actors_%s ();', n)
+FROM generate_series(1, 450) n -- 500 is the upper limit for table not found error hint generation
+\gexec
+
+-- TODO add many function for fuzzy search (somehow this is making the loadtest start slow)