Support for TypedSQL "prisma generate --sql"

[joonatanvanhala]

It seems that currently the code generates the client without the --sql flag so the package doesn't include the sql files.

 generateCommand() {
    let command = 'npx prisma generate';
    if (this.isDataProxyParam()) {
      this.serverless.cli.log(`Prisma data proxy is enabled.`);
      command += ' --data-proxy';
    }
    return command;
  }