[BUG] ```ClusterCollection``` object has no attribute ```metadata```

[HeetVekariya]

Additional Information

• This issue is originally found in Issue 3925. Please have a look in that conversation.

Expected behavior

• ClusterCollection object/instance has metadata parameter associated with it. We can check here.
• Hence metadata of ClusterCollection object/instance should be accessible.

Actual behavior

• When we try to access metadata of ClusterCollection object/instance then it gives below error

[<class 'MDAnalysis.analysis.encore.clustering.ClusterCollection.ClusterCollection'>, <class 'MDAnalysis.analysis.encore.clustering.ClusterCollection.ClusterCollection'>]

Traceback (most recent call last): File "/home/heet/Work/Development/mdanalysis/test.py", line 27, in print([cluster.metadata for cluster in cluster_collection][:2]) File "/home/heet/Work/Development/mdanalysis/test.py", line 27, in print([cluster.metadata for cluster in cluster_collection][:2])

AttributeError: 'ClusterCollection' object has no attribute 'metadata'

## Code to reproduce the behavior ##
- Below code is from **```cluster.py```** ( [here](https://github.com/MDAnalysis/mdanalysis/blob/734314b8b7b70617a92eb505f75844e6837505ca/package/MDAnalysis/analysis/encore/clustering/cluster.py#L147) ).

```python
from MDAnalysis import Universe
import MDAnalysis.analysis.encore as encore
from MDAnalysis.tests.datafiles import PSF, DCD, DCD2
ens1 = Universe(PSF, DCD)
ens2 = Universe(PSF, DCD2)
cluster_collection = encore.cluster([ens1,ens2])

cluster_collection = encore.cluster([ens1,ens2], method=encore.DBSCAN())

cluster_collection = encore.cluster([ens1,ens2], method=[encore.AffinityPropagationNative(preference=-1.), encore.AffinityPropagationNative(preference=-2.)])

print([cluster.metadata for cluster in cluster_collection][:2])

Current version of MDAnalysis

• Which version are you using? (run python -c "import MDAnalysis as mda; print(mda.__version__)")
  • 2.6.1
• Which version of Python (python -V)?
  • Python 3.10.13
• Which operating system?
  • Ubuntu

[IAlibay]

Migrating to mdaencore, this is no longer in the realm of the core library.

[IAlibay]

@HeetVekariya to explain the migration - future development of the encore code now happens here, and potentially backported to the core library as necessary.