The goal of this ticket is to adjust the balancingEnabled field return by $listClusterCatalog, so that:

• It's false whenever the fields `noBalance` or `permitMigrations` of a collection are blocking the balancer.
• It doesn't depend on the value of the global balancing status.

In addition, we'll add a field called `balancingEnabledReason` to expose the status of `noBalance` and `permitMigration` flags separately.

The format of this new field will be:

balancingEnabledReason: {
    'enableBalancing': <true or false>,
    'allowMigrations': <true or false>
} 

• enableBalancing will depend on the `noBalance` field.
• allowMigrations will depend on the `permitMigrations` field.

Note that this is necessary because, currently, a user can enable the balancing of a collection through 2 different ways:

• setAllowMigrations - which will be deprecated soon - this command updates the `permitMigrations` flag.
• configureCollectionBalancing - which introduced the option of enabling the balancing of a coll in v8.1 - this command updates the `noBalance` flag.