adds position and last token context to parse errors
adds position and last token context to parse errors

Signed-off-by: cmoog <4c0673e29781d765b3f6f85458b296cf7e72ad8e@gmail.com>

mahak/vitess,vitessio/vitess,mahak/vitess,tinyspeck/vitess,tinyspeck/vitess,tinyspeck/vitess,mahak/vitess,vitessio/vitess,vitessio/vitess,vitessio/vitess,vitessio/vitess,vitessio/vitess,mahak/vitess,tinyspeck/vitess,vitessio/vitess,vitessio/vitess,tinyspeck/vitess,mahak/vitess,mahak/vitess,mahak/vitess,tinyspeck/vitess,tinyspeck/vitess,mahak/vitess