[ENH] Support for scattered precomputed distance matrix for MNMG DBSCAN

[Nyrio]

Support for precomputed distance matrices in DBSCAN was added in #3585
The precomputed distance matrix is quadratic in size, which means two things:

• If you can fit it in memory, your dataset is probably too small to take advantage of MNMG.
• Sending the complete matrix to all the nodes is long and therefore MNMG is currently extremely slow.

Is there a use case for supporting a distance matrix that is scattered across the nodes (solves both points above)? It will require changing the API a bit, as well as the kernels.

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[github-actions]

This issue has been labeled inactive-90d due to no recent activity in the past 90 days. Please close this issue if no further response or action is needed. Otherwise, please respond with a comment indicating any updates or changes to the original issue and/or confirm this issue still needs to be addressed.