feat: add default lang and scope on plugin configuration for i18n custom block

[userquin]

Is your feature request related to a problem?

It is not a problem, it is a new feature.

Describe the solution you'd like

When using i18n custom block resources inside the sfc components, it is a pain writing global and lang attributes: provide a way on plugin configuration to specify default scope and lang.

When using i18n with src external resource, it is also a pain to add global scope.

With these options added to plugin configuration, we have to write less code on each sfc component.

Also, the plugin should override default ones if provided on i18n custom block.

This feature shoundn't be present when using src attribute of i18n custom block: only scope.

You can see an example for lang on vite-plugin-pages repo for route lang attribute (route is also a custom block similar to i18n).

Describe alternatives you've considered

I have no consider alternatives, should be on this plugin.

Additional context

No more context required.

[userquin]

I'm open to make a PR... I'm working on a PR... PR done