feat: extend support for create function

[cvng]

What kind of change does this PR introduce?

extend support for create function

What is the current behavior?

panics with SETOF panics with STRICT | RETURNS NULL ON NULL INPUT | CALLED ON NULL INPUT

What is the new behavior?

parser returns - added tests

Additional context

View log

```rust CreateFunctionStmt { is_procedure: false, replace: false, funcname: [ Node { node: Some( String( String { sval: "getfoo", }, ), ), }, ], parameters: [ Node { node: Some( FunctionParameter( FunctionParameter { name: "", arg_type: Some( TypeName { names: [ Node { node: Some( String( String { sval: "pg_catalog", }, ), ), }, Node { node: Some( String( String { sval: "int4", }, ), ), }, ], type_oid: 0, setof: false, pct_type: false, typmods: [], typemod: -1, array_bounds: [], location: 23, }, ), mode: FuncParamDefault, defexpr: None, }, ), ), }, ], return_type: Some( TypeName { names: [ Node { node: Some( String( String { sval: "users", }, ), ), }, ], type_oid: 0, setof: true, pct_type: false, typmods: [], typemod: -1, array_bounds: [], location: 58, }, ), options: [ Node { node: Some( DefElem( DefElem { defnamespace: "", defname: "language", arg: Some( Node { node: Some( String( String { sval: "sql", }, ), ), }, ), defaction: DefelemUnspec, location: 80, }, ), ), }, Node { node: Some( DefElem( DefElem { defnamespace: "", defname: "as", arg: Some( Node { node: Some( List( List { items: [ Node { node: Some( String( String { sval: "select * from \"users\" where users.id = $1;", }, ), ), }, ], }, ), ), }, ), defaction: DefelemUnspec, location: 109, }, ), ), }, ], sql_body: None, } ```