Migrations with "--" in text strings fail

Hi @FilledStacks,
First off, I love all your content! But my query below is failing when using this plugin because it has a string that contains "--". I think https://github.com/FilledStacks/sqflite_migration/blob/396b9a762054157b00cd5bc6b01739ab17428b15/lib/src/database_migration_service.dart#L29-L40 is the problem because it doesn't take situations where "--" might be valid. For example,

```sql
CREATE TABLE Assets (
id INTEGER NOT NULL PRIMARY KEY
,filePath TEXT NOT NULL
,nameSingular TEXT NOT NULL
,namePlural TEXT NOT NULL
,sourceUrl TEXT NOT NULL
,active INTEGER NOT NULL DEFAULT 1
);

INSERT INTO Assets (
id
,filePath
,nameSingular
,namePlural
,sourceUrl
,active
) VALUES (
1
,'assets/svg/openclipart.com/francesco_rollandin/Architetto----Dino-08.svg' -- notice the '----' in the path
,'Dinosaur'
,'Dinosaurs'
,'https://openclipart.org/detail/25749/architetto-dino-08'
,1
);
```

This isn't a total deal-breaker in my case because I can just change the filename, but others may run into this issue and be like, AAAAAAAAAHHHHHH!!!!!!

Thanks to everyone at FilledStacks!