Run same options transform on generate for bundle

[diervo]

Some recent changes introduced in 0.43.0 breaks the amd named module generation.

The checkOptions function is applied only on the main entry point (rollup), but not in the generate() function.

Basically when passing this options:

// Passing a set of options
rollup({ entry, plugins, ..otherOptions }).then(() => {
    ... 
   // Passing another set of options
    bundle.generate({ format: 'amd', moduleId: 'something' });
    ...

The output does respect the moduleId option, nor does it error out.

This change addresses this inconsistency, and it will give the same warning.

We tried to add a tests but the tests makes the assumption that both entry points rollup and bundle will receive the same options object, which is not necessarily imposed in the API.

//cc @pmdartus who coPR this.

[Rich-Harris]

Thank you!