feat: allow calls to plural function in no-expression-in-message

[tstehr]

Lingui allows to embed the plural macro inside the t macro, creating a message that includes the plural, similar to nested plurals.

For an example consider the following macro call:

import { plural, t } from '@lingui/macro';
const message = t`Count: ${plural(count, {
  one: '# book',
  other: '# books',
})}`;

It gets represented in the message catalog as a single message: Count: {count, plural, one {# book} other {# books}}.

However the no-expression-in-message rule currently forbids this pattern since the expression in the template string is not an identifier. This PR changes that behavior, allowing calls to the plural function to occur inside the t macro.

[andrii-bodnar]

@tstehr thank you and congrats on your first contribution! 🎉

[timofei-iatsenko]

Thanks for contribution, it also should be expanded for other macros, such as select and selectOrdinal

[andrii-bodnar]

@tstehr would you like to add the select and selectOrdinal support within the current PR?

[tstehr]

@tstehr would you like to add the select and selectOrdinal support within the current PR?

I've opened up #54 to do that