[CBM] --map-data should not be needed if collection is excluded

What is the problem?
If you create a repository and exclude a collection and then restore backups from it to a cluster where the collections have different IDs then cbbackupmgr will ask you to use --map-data on the excluded collection, even though it will not be restored.

What is the solution?
When looking for collection conflicts we should ignore collections in the repository's config that have been excluded.

Reproduction

1. Create two collections, C1 and C2 on a cluster
2. Create a repository with --exclude-data default._default.c2
3. Do a backup
4. Recreate the bucket and collections but create C2 before C1
5. Try to restore the backup

Workaround
-include-data/-exclude-data on the restore fixes this