INDEXED BY and NOT INDEXED after a table name are parse errors #2762

SQLite's INDEXED BY name and NOT INDEXED after a table name are parse errors. Seen in the sqllogictest run (evidence/slt_lang_aggfunc.test and others), reproduced on develop (06211a0):

alasql('CREATE TABLE t1 (x INTEGER)');
alasql("SELECT group_concat(x, ':') FROM t1 NOT INDEXED");   // Parse error
alasql('SELECT x FROM t1 INDEXED BY t1i1');                  // Parse error

Both are hints about index use and do not change the result in SQLite, so accepting them (and ignoring them) would make SQLite queries run.

Not breaking: they have never parsed.