Cannot allow paths starting with ./ in no-internal-modules

Due to the following filter:

https://github.com/import-js/eslint-plugin-import/blob/cd957286efe1c4aa0423f82ac5576c75fd3be71e/src/rules/no-internal-modules.js#L63

There is no way to match relative paths with the `no-internal-modules` rule, thus exporting any files from subdirectories in any index.ts file triggers an error. The above filter prevents rules like `./**` which would solve this issue.

I'm using Angular for my project which is irrelevant, other than the common filesystem pattern that this issue affects:

```ts
/* No error */
export { ContactModule } from './contact.module';

/* Reaching to "./components/contact-card/contact-card.component" is not allowed. eslint(import/no-internal-modules) */
export { ContactCardComponent } from './components/contact-card/contact-card.component';
```

Start by reading src/rules/no-internal-modules.js at the filter linked in the issue and reproduce the rule with a relative glob such as ./**. Trace the existing rule coverage, then add regression coverage for relative paths; done means exports from nested relative paths no longer trigger the rule when the pattern explicitly allows them.

Written by the indexing model from the issue text.