Remove "SQL" prefix from types

The rationale here is the same as the last commit: since this crate
exclusively parses SQL, there's no need to restate that in every type
name. (The prefix seems to be an artifact of this crate's history as a
submodule of Datafusion, where it was useful to explicitly call out
which types were related to SQL parsing.)

This commit has the additional benefit of making all type names
consistent; over type we'd added some types which were not prefixed with
"SQL".

examples/cli.rs

@@ -30,10 +30,10 @@ fn main() {
     );
 
     let dialect: Box<dyn Dialect> = match std::env::args().nth(2).unwrap_or_default().as_ref() {
-        "--ansi" => Box::new(AnsiSqlDialect {}),
+        "--ansi" => Box::new(AnsiDialect {}),
         "--postgres" => Box::new(PostgreSqlDialect {}),
         "--ms" => Box::new(MsSqlDialect {}),
-        "--generic" | "" => Box::new(GenericSqlDialect {}),
+        "--generic" | "" => Box::new(GenericDialect {}),
         s => panic!("Unexpected parameter: {}", s),
     };