Make optional reporting of "import/export: Multiple exports of name ..."

Multiple exports of name is always reported as an error but it's a legitimate feature disciplined by ECMASCRIPT specs.

Es:

```
// D.js
const f = () => 'D::f'
export { f }

// E.js
export * from './D.js'
const f = () => 'E::f'
export { f }
```

Report -> import/export: Multiple exports of name 'f'.

Maybe eslint-plugin-import could give an optionable error that can ben disabled by config?

[See also here](https://stackoverflow.com/questions/66533367/import-export-name-collision-resolution) and #1704

Locate the rule that emits the “import/export: Multiple exports of name” message and read its handling of the provided re-export example. Determine where rule configuration is defined, then add an opt-out setting and verify that the example is suppressed when it is disabled while existing reporting remains unchanged.

Written by the indexing model from the issue text.