Added function to select samples that are similar to a given reference sample

[mhkc]

The PR adds a function to lookup samples with a similar minhash distance to all other samples.

How to setup and perform the tests

1. Setup Bonsai
2. Load a few samples to the database and ensure that the signature files are uploaded as well
3. Goto /groups
4. Select one sample, use the button to find X number of similar samples in the list
5. Goto the sample view of a sample. Verify that a dendrogram with similar samples are displayed.

Expected outcome

• When clicked the X most similar samples should be selected.
• The option should only be available when one sample is selected.

Additional context