iGenVar - Cluster SVs (deletions)

[Irallia]

Remove duplicates and cluster deletions with similar breackends.

We already have a simple method, but as discussed in #82 (comment), it has some clear disadvantages. The following issues describe different cluster principles.

• First we should decouple junctions and a cluster of junctions.

Than we should implement different methods:

• 1: hierarchical clustering [FEATURE] Cluster junctions by hierarchical clustering #54,
• 2: self-balancing binary tree [FEATURE] Cluster junctions by a self-balancing binary tree #55,
• 3: candidate selection based on voting [FEATURE] Cluster junctions by candidate selection based on voting #56