feat: distance-based task distribution logic

[Ayush5120]

Added task distribution logic, that computes the total distance between the set of input URIs (from the incoming TES task) and the available TES instances, then relays the task to the closest TES instance.

[uniqueg]

Thanks @Ayush5120. There are quite some comments I made. Please address those and let's have another round of review after.

[uniqueg]

Great - we're getting there! :)
I think all the remaining issues are small fry that shouldn't take long to address

[uniqueg]

Thanks a lot @Ayush5120. I didn't try it out, really, but it looks good to me and I will merge it. I hope edge cases (e.g., no inputs at all) will work. But if not, we can fix them after merging. Note that I have opened #124 to handle middleware more gracefully and generically. It's not an urgent issue, though - we can take care of it after #123 and #122.

[uniqueg]

Hi @Ayush5120. Thanks a lot for the great work :)

I am merging now, as I guess you have addressed at least most of the comments (and I have opened #124). If there are any more issues popping up during testing, we can open individual issues for them and fix them :)

In the future, I think it's best if you resolve open conversations yourself if you feel confident that you have addressed them non-controversially. Otherwise, please leave a comment, either describing how you addressed it, or why you did not address it. That makes reviewing a whole lot easier.