Proposal: Allow to hide a specific user's post or arbitrary posts using thresholds

## Feature Request Form
from https://groups.google.com/forum/?utm_medium=email&utm_source=footer#!topic/hypothesis-forum/5lyO8q6-jLQ

On Sunday, October 15, 2017 at 5:08:26 PM UTC-7, Mathieu Beliveau wrote:
Hi,

I quick search unfortunately returned no result regarding this post's title, forgive me if this feature might have been requested times and times again.

One thing I'm noticing while using this application is that, on a given site, some user may embark on a trolling campaign or just flood the panel with low quality comments while not exactly granting a case for calling a moderator. In those cases, I think it would be very nice to have the ability to hide this specific user's posts until specified otherwise (this would be local to my account).

As the plaform gets more and more popular (I sure hope it gets enough momentum for it to be really a nice extension to have on any given web page or document); I'm pretty certain that these kind of filters will prove essential.

In the same vein, a post rating system similar to what slashdot offers would be very appreciated to find the comments deemed the most useful while leaving the most toxic ones (like slashdot, it would be nice if I could configure my viewing of the posts panel using some treshold to show and hide different posts).

Thanks!

Start by reviewing the linked Google Groups discussion and the product-backlog context; no implementation files or tests are identified. Clarify the requirements for per-account user hiding, arbitrary post thresholds, and rating behavior, then define acceptance criteria for the filtering experience before implementation.

Written by the indexing model from the issue text.